71M6541F-DB

71M6541 Demo Board REV 3.0 User’s Manual Rev 4.0; 12/12 Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000 © 2012 Maxim Integrated Products, Inc. Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. 71M6541 Demo Board REV 3.0 User’s Manual Table of Contents 1 GETTING STARTED................................................................................................................................................ 5 1.1 General .................................................................................................................................................................... 5 1.2 Safety and ESD Notes ............................................................................................................................................ 5 1.3 Demo Kit Contents ................................................................................................................................................. 6 1.4 Demo Board Versions ............................................................................................................................................ 6 1.5 Compatibility........................................................................................................................................................... 6 1.6 Suggested Equipment not Included ..................................................................................................................... 6 1.7 Demo Board Test Setup ......................................................................................................................................... 7 1.7.1 Power Supply Setup .......................................................................................................................................... 8 1.7.2 Cables for Serial Communication ...................................................................................................................... 8 1.7.3 Checking Operation........................................................................................................................................... 9 1.7.4 Serial Connection Setup.................................................................................................................................... 9 1.8 Using the Demo Board ......................................................................................................................................... 10 1.8.1 Serial Command Language ............................................................................................................................. 11 1.8.2 Using the Demo Board for Energy Measurements .......................................................................................... 17 1.8.3 Adjusting the Kh Factor for the Demo Board ................................................................................................... 17 1.8.4 Adjusting the Demo Boards to Different SHUNT Resistors ............................................................................. 17 1.8.5 Using the Pre-Amplifier ................................................................................................................................... 17 1.8.6 Using Current Transformers (CTs) .................................................................................................................. 17 1.8.7 Implementing a Single-Phase 3-Wire Meter (EQU 1) ...................................................................................... 17 1.8.8 Adjusting the Demo Boards to Different Voltage-Dividers ............................................................................... 17 1.9 Calibration Parameters ........................................................................................................................................ 18 1.9.1 General Calibration Procedure ........................................................................................................................ 18 1.9.2 Calibration Macro File ..................................................................................................................................... 19 1.9.3 Updating the Demo Code (hex file) ................................................................................................................. 19 1.9.4 Updating Calibration Data in Flash or EEPROM ............................................................................................. 20 1.9.5 Loading the Code for the 71M6541 into the Demo Board ............................................................................... 20 1.9.6 The Programming Interface of the 71M6541 ................................................................................................... 22 1.10 Demo Code ........................................................................................................................................................ 23 1.10.1 Demo Code Description ............................................................................................................................... 23 1.10.2 Important MPU Addresses ........................................................................................................................... 23 1.10.3 LSB Values in CE Registers ........................................................................................................................ 30 1.10.4 Calculating IMAX and Kh ............................................................................................................................. 30 1.10.5 Determining the Type of 71M6x0x ............................................................................................................... 31 1.10.6 Communicating with the 71M6X0X .............................................................................................................. 32 1.10.7 Bootloader Feature ...................................................................................................................................... 32 2 APPLICATION INFORMATION ............................................................................................................................. 34 2.1 Sensor Connections and Equations ................................................................................................................... 34 2.1.1 Sensor Wiring .................................................................................................................................................. 34 2.1.2 Single-phase two-wire (EQU 0) ....................................................................................................................... 35 2.1.3 Single-phase three-wire (EQU 1) .................................................................................................................... 36 2.2 Calibration Theory ................................................................................................................................................ 37 2.2.1 Calibration with Three Measurements ............................................................................................................. 37 2.2.2 Calibration with Five Measurements ............................................................................................................... 38 2.3 Calibration Procedures ........................................................................................................................................ 40 2.3.1 Calibration Equipment ..................................................................................................................................... 40 2.3.2 Phase-by-Phase Calibration ............................................................................................................................ 40 2.3.3 Detailed Calibration Procedures ...................................................................................................................... 40 2.3.4 Calibration Procedure with Three Measurements ........................................................................................... 41 2 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 2.3.5 Calibration Procedure with Five Measurements .............................................................................................. 42 2.3.6 Calibration Spreadsheets ................................................................................................................................ 42 2.3.7 Compensating for Non-Linearities ................................................................................................................... 45 2.4 Temperature Compensation ................................................................................................................................ 46 2.4.1 Error Sources .................................................................................................................................................. 46 2.4.2 Software Features for Temperature Compensation ........................................................................................ 47 2.4.3 Calculating Parameters for Compensation ...................................................................................................... 48 2.5 Testing the Demo Board ...................................................................................................................................... 51 2.5.1 Functional Meter Test...................................................................................................................................... 51 2.6 Sensors and Sensor Placement .......................................................................................................................... 53 2.6.1 Self-Heating .................................................................................................................................................... 53 2.6.2 Placement of Sensors (ANSI) ......................................................................................................................... 54 2.6.3 Placement of Sensors (IEC) ............................................................................................................................ 55 2.6.4 Other Techniques for Avoiding Magnetic Crosstalk......................................................................................... 56 3 HARDWARE DESCRIPTION................................................................................................................................. 58 3.1 71M6541-DB Description: Jumpers, Switches and Test Points ....................................................................... 58 3.2 Board Hardware Specifications .......................................................................................................................... 62 4 APPENDIX ............................................................................................................................................................. 64 4.1 71M6541-DB Electrical Schematic ...................................................................................................................... 65 4.2 71M6541-DB Bill of Material................................................................................................................................. 67 4.3 71M6541-DB PCB Layout ..................................................................................................................................... 69 4.4 71M6541 Pinout Information................................................................................................................................ 73 4.5 Revision History ................................................................................................................................................... 76 List of Figures Figure 1-1: D6541 REV2.0 Demo Board with Debug Board: Basic Connections ................................................................ 7 Figure 1-2: HyperTerminal Sample Window with Disconnect Button (Arrow) ................................................................... 10 Figure 1-3: Port Speed and Handshake Setup (left) and Port Bit setup (right) .................................................................. 10 Figure 1-4: Typical Calibration Macro File ......................................................................................................................... 19 Figure 1-5: Emulator Window Showing Reset and Erase Buttons (see Arrows) ............................................................... 21 Figure 1-6: Emulator Window Showing Erased Flash Memory and File Load Menu......................................................... 21 Figure 2-1: Shunt Connections.......................................................................................................................................... 34 Figure 2-2: Single-Phase Two-Wire Meter with Shunt Sensor .......................................................................................... 35 Figure 2-3: Single-Phase Two-Wire Meter with two Shunt Sensors .................................................................................. 35 Figure 2-4: Single-Phase Three-Wire Meter with two Shunt Sensors ............................................................................... 36 Figure 2-4: Watt Meter with Gain and Phase Errors.......................................................................................................... 37 Figure 2-5: Phase Angle Definitions .................................................................................................................................. 40 Figure 2-7: Calibration Spreadsheet for Three Measurements ......................................................................................... 43 Figure 2-8: Calibration Spreadsheet for Five Measurements ............................................................................................ 44 Figure 2-9: Non-Linearity Caused by Quantification Noise ............................................................................................... 45 Figure 2-10: GAIN_ADJ over Temperature ........................................................................................................................ 49 Figure 2-11: GAIN_ADJ and GAIN_ADJ’ over Temperature .............................................................................................. 49 Figure 2-12: Meter with Calibration System ...................................................................................................................... 52 Figure 2-13: Calibration System Screen ........................................................................................................................... 52 Figure 2-14: Wh Load Lines at Room Temperature with 71M6201 and 50 µΩ Shunts ..................................................... 53 Figure 2-15: Typical Sensor Arrangement (left), Recommended Arrangement (right) ...................................................... 55 Figure 2-16: Improved Sensor Arrangement ..................................................................................................................... 55 Figure 2-17: Loop Formed by Shunt and Sensor Wire ...................................................................................................... 56 Figure 2-18: Shunt with Compensation Loop .................................................................................................................... 56 3 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual Figure 2-19: Shunt with Center Drill Holes ........................................................................................................................ 56 Figure 3-1: 71M6541-DB REV 3.0 - Board Description ..................................................................................................... 61 Figure 4-1: 71M6541-DB REV 3.0 Demo Board: Electrical Schematic 1/2 ....................................................................... 65 Figure 4-2: 71M6541-DB REV 3.0 Demo Board: Electrical Schematic 2/2 ....................................................................... 66 Figure 4-3: 71M6541-DB REV 3.0: Top View ................................................................................................................... 69 Figure 4-4: 71M6541-DB REV 3.0: Top Copper ............................................................................................................... 70 Figure 4-5: 71M6541-DB REV 3.0: Bottom View .............................................................................................................. 71 Figure 4-6: 71M6541-DB REV 3.0: Bottom Copper .......................................................................................................... 72 Figure 4-14: 71M6541, LQFP64: Pinout (Top View) ......................................................................................................... 75 List of Tables Table 1-1: Jumper Settings on Debug Board ...................................................................................................................... 8 Table 1-2: Straight Cable Connections ............................................................................................................................... 8 Table 1-3: Null-modem Cable Connections ........................................................................................................................ 8 Table 1-4: CE RAM Locations for Calibration Constants .................................................................................................. 19 Table 1-5: Flash Programming Interface Signals .............................................................................................................. 22 Table 1-6: MPU XRAM Locations ..................................................................................................................................... 24 Table 1-7: Bits in the MPU Status Word............................................................................................................................ 29 Table 1-8: CE Registers and Associated LSB Values ....................................................................................................... 30 Table 1-9: IMAX for Various Shunt Resistance Values and Remote Sensor Types.......................................................... 31 Table 1-10: Identification of 71M6X0X Remote Sensor Types .......................................................................................... 32 Table 2-1: Temperature-Related Error Sources ................................................................................................................ 46 Table 2-2: Temperature-Related Error Sources ................................................................................................................ 50 Table 3-1: 71M6541-DB REV 3.0 Description ................................................................................................................... 60 Table 4-1: 71M6541-DB REV 3.0: Bill of Material ............................................................................................................. 67 Table 4-3: 71M6541 Pin Description Table 1/3 ................................................................................................................. 73 Table 4-4: 71M6541 Pin Description Table 2/3 ................................................................................................................. 73 Table 4-5: 71M6541 Pin Description Table 3/3 ................................................................................................................. 74 4 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 1 1 GETTING STARTED 1.1 GENERAL The Maxim Integrated 71M6541-DB REV 3.0 Demo Board is a demonstration board for evaluating the 71M6541 device for single-phase electronic energy metering applications in conjunction with the Remote Sensor Interface. It incorporates a 71M6541 integrated circuit, a 71M6601 Remote Interface IC, peripheral circuitry such as a serial EEPROM, emulator port, and on-board power supply. A serial to USB converter allows communication to a PC through a USB port. The Demo Board allows the evaluation of the 71M6541 energy meter chip for measurement accuracy and overall system use. The board is pre-programmed with a Demo Program (Demo Code) in the FLASH memory of the 71M6541F IC. This embedded application is developed to exercise all low-level function calls to directly manage the peripherals, flash programming, and CPU (clock, timing, power savings, etc.). The 71M6541F IC on the Demo Board is pre-programmed and pre-calibrated for the 50 µΩ or 120 µΩ shunt shipped with the board. The Demo Board may also be used for operation with a CT after hardware modifications that can be easily performed by the user. This configuration will require a different version of the Demo Code. 1.2 SAFETY AND ESD NOTES Connecting live voltages to the demo board system will result in potentially hazardous voltages on the demo board. THE DEMO SYSTEM IS ESD SENSITIVE! ESD PRECAUTIONS SHOULD BE TAKEN WHEN HANDLING THE DEMO BOARD! EXTREME CAUTION SHOULD BE TAKEN WHEN HANDLING THE DEMO BOARD ONCE IT IS CONNECTED TO LIVE VOLTAGES! BOARD GROUND IS CLOSE TO LIVE VOLTAGE! CAUTION: THE PHASE A CONNECTION OF THE DEMO BOARD IS CONNECTED TO THE LIVE VOLTAGE SHUNT. THE NEUTRAL SHUNT IS ISOLATED VIA THE 71M6X0X REMOTE SENSOR INTERFACE AND CONNECTED TO THE PHASE B INPUT. EXTREME CARE MUST BE TAKEN WHEN CHANGING SHUNT AND VOLTAGE CONNECTIONS! 5 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 1.3 DEMO KIT CONTENTS • • • • • Demo Board D6541 REV 3.0 containing one 71M6601 or 71M6201 Remote Sensor Interface and one 71M6541F IC with pre-loaded demo program 5VDC/1,000mA universal wall transformer with 2.5mm plug (Switchcraft 712A compatible) Serial-USB converter USB cable ANSI base with 50 μΩ shunt resistor (optional, for ANSI kits only) or two 120 μΩ shunt resistors 1.4 DEMO BOARD VERSIONS This manual applies to D6541 REV 3.0 only. 1.5 COMPATIBILITY This manual applies to the following hardware and software revisions: • • • 71M6541 chip revision B02 Demo Kit firmware revision 5.4G or later Demo Board D6541 REV 3.0 1.6 SUGGESTED EQUIPMENT NOT INCLUDED For functional demonstration: • PC with Windows® 2000, Windows XP®, or Windows 7 operating system, equipped with USB port. For the use of the optional Debug Board, a serial interface (COM port) is required. For software development (MPU code): • • Signum Systems In-Circuit Emulator (ICE): ADM-51 o Signum WEMU51 version 3.11.09 or later should be used. Keil 8051 “C” Compiler Kit: CA51 Windows and Windows XP are registered trademarks of Microsoft Corp. 6 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 1.7 DEMO BOARD TEST SETUP Figure 1-1 shows the basic connections of the Demo Board plus optional Debug Board with the external equipment. The PC can be connected via the USB Interface (CN1). For stand-alone testing (without AC voltage) the Demo Board maybe powered via the 5.0 VDC input (J20). The optional Debug Board must be powered with its own 5 VDC power supply. DEMONSTRATION METER 6541 Single Chip Meter PULSE OUTPUTS N Wh L SEGDIO0/WPULSE External Shunts SEGDIO1/VPULSE J3 IAP IAN IA SEGDIO6/XPULSE SEGDIO7/YPULSE V3P3SYS VARh V3P3SYS PULSE A PULSE B J1 3.3V or 5V LCD Load IBP IBN 6601 IB SDCK SDATA EEPROM J5 SPI Connector J19 V3P3A V3P3SYS ICE Connector J14 NEUTRAL VA 5.0 VDC Input J21 DEBUG BOARD (OPTIONAL) MPU HEARTBEAT (5Hz) 1 SEGDIO52 JP6 Power Supply JP20 CE HEARTBEAT (1Hz) V5_DBG 2 SEGDIO10 GND LINE V5_DBG OPTO OPTO GND 3 GND_DBG V5_DBG OPTO V3P3 10 TX J13 Battery 2 (optional) PB J12 JP56 RESET VBAT_RTC OPTO RX OPTO RTM INTERFACE GND 5, 7, 9, 11 PB RESET DB9 to PC COM Port RS-232 INTERFACE 12 TMUXOUT 8 TMUX2OUT V3P3D 6 J5 FPGA 68 Pin Connector OPTO VBAT Battery 1 (optional) On-board components powered by V3P3D 6 OPTO 4 V5_DBG 15, 16 5V DC 13, 14 GND_DBG JP5 V5_NI JP21 06/03/2010 USB Interface CN1 Isolator Serial/USB Converter IsoGND Figure 1-1: 71M6541-DB REV3.0 Demo Board with optional Debug Board: Basic Connections The Demo Board contains all circuits necessary for operation as a meter, including display, calibration LEDs, and internal power supply. Communication with a PC USB port is provided via connector CN1. The optional Debug Board uses a separate power supply, and is optically isolated from the Demo Board. It interfaces to a PC through the USB connector. It is recommended to set up the demo board with no live AC voltage connected, and to connect live AC voltages only after the user is familiar with the demo system. All input signals are referenced to the V3P3A (3.3V power supply to the chip). 7 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 1.7.1 POWER SUPPLY SETUP There are several choices for the meter power supply: o o Internal (using the AC line voltage). The internal power supply is only suitable when the voltage exceeds 100V RMS. To enable the internal supply, a jumper needs to be installed across JP6 on the top of the board. External 5.0VDC connector (J20) on the Demo Board. 1.7.2 CABLES FOR SERIAL COMMUNICATION 1.7.2.1 USB Connection (Recommended) A standard USB cable can be used to connect the Demo Board to a PC running HyperTerminal or a similar serial interface program. A suitable driver, e.g., the FTDI CDM Driver Package, must be installed on the PC to enable the USB port to be mapped as a virtual COM port. The driver can be found on the FTDI web site (www.ftdichip.com). See Table 3-1 for correct placement of jumper JP5 depending on whether the USB connection or the serial connection via the Debug Board is used. 1.7.2.2 Serial Connection (via Optional Debug Board) For connection of the DB9 serial port of the Debug Board to a PC serial port (COM port), either a straight or a so-called “null-modem” cable may be used. JP1 and JP2 are plugged in for the straight cable, and JP3/JP4 are empty. The jumper configuration is reversed for the null-modem cable, as shown in Table 1-1. Cable Configuration Mode Straight Cable Null-Modem Cable Jumpers on Debug Board JP1 JP2 JP3 JP4 Default Installed Installed -- -- Alternative -- -- Installed Installed Table 1-1: Jumper Settings on Debug Board JP1 through JP4 can also be used to alter the connection when the PC is not configured as a DCE device. Table 1-2 shows the connections necessary for the straight DB9 cable and the pin definitions. PC Pin Function Demo Board Pin 2 TX 2 3 RX 3 5 Signal Ground 5 Table 1-2: Straight Cable Connections Table 1-3 shows the connections necessary for the null-modem DB9 cable and the pin definitions. PC Pin Function Demo Board Pin 2 TX 3 3 RX 2 5 Signal Ground 5 Table 1-3: Null-modem Cable Connections See Table 3-1 for correct placement of jumper JP5 on the Demo Board depending on whether the USB connection or the serial connection via the Debug Board is used. 8 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 1.7.3 CHECKING OPERATION A few seconds after power up, the LCD display on the Demo Board should display a brief greeting in the top row and the demo code revision in the bottom row: H E L L 5. 4 G 0 The “HELLO” message should be followed by the display of accumulated energy: 0. 0 0 0 Wh SYS 3 The “SYS” symbol will be blinking, indicating activity of the MPU inside the 71M6541. In general, the fields of the LCD are used as shown below: Measured value Command number (Phase) Unit 1.7.4 SERIAL CONNECTION SETUP After connecting the USB cable from the Demo Board to the PC, or after connecting the serial cable from the optional Debug Board to the PC, start the HyperTerminal application and create a session using the following parameters: Port Speed: 9600 bd Data Bits: 8 Parity: None Stop Bits: 1 Flow Control: XON/XOFF When using the USB connection, you may have to define a new port in HyperTerminal after selecting File  Properties and then clicking on the “Connect Using“ dialog box. If the USB-to-serial driver is installed (see section 1.7.2.1) a port with a number not corresponding to an actual serial port, e.g., COM5, will appear in the dialog box. This port should be selected for the USB connection. HyperTerminal can be found by selecting Programs Accessories  Communications from the Windows start menu. The connection parameters are configured by selecting File  Properties and then by pressing the Configure button. Port speed and flow control are configured under the General tab (Figure 1-3, left), bit settings are configured by pressing the Configure button (Figure 1-3, right), as shown below. A setup file (file name “Demo Board Connection.ht”) for HyperTerminal that can be loaded with File  Open is also provided with the tools and utilities. Port parameters can only be adjusted when the connection is not active. The disconnect button, as shown in Figure 1-2 must be clicked in order to disconnect the port. 9 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual Figure 1-2: HyperTerminal Sample Window with Disconnect Button (Arrow) Figure 1-3: Port Speed and Handshake Setup (left) and Port Bit setup (right) Once, the connection to the demo board is established, press and the command prompt, >, should appear. Type >? to see the Demo Code help menu. Type >i to verify the demo code revision. 1.8 USING THE DEMO BOARD The 71M6541 Demo Board is a ready-to-use meter prepared for use with external shunt resistors. Demo Code versions for single-phase two-wire operation (EQU 0, with secondary tamper sensor) and for single-phase three-wire operation (ANSI configuration, EQU 1) are provided by Maxim Integrated. Demo Boards in ANSI configuration are preloaded with Demo Code for EQU 1, Demo Boards in IEC configuration are preloaded with Demo Code for EQU 0. Using the Demo Board involves communicating with the Demo Code via the command line interface (CLI). The CLI allows all sorts of manipulations to the metering parameters, access to the EEPROM, selection of the displayed parameters, changing calibration factors and many more operations. Before evaluating the 71M6541 on the Demo Board, users should get familiar with the commands and responses of the CLI. A complete description of the CLI is provided in section 1.8.1. 10 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 1.8.1 SERIAL COMMAND LANGUAGE The Demo Code residing in the flash memory of the 71M6541 provides a convenient way of examining and modifying key meter parameters via its command line interface (CLI). The tables in this chapter describe the commands in detail. Commands for CE Data Access: ] CE DATA ACCESS Description: Allows user to read from and write to CE data space. Usage: ] [Starting CE Data Address] [option]…[option] Command combinations: ]A??? Read consecutive 16-bit words in Decimal, starting at address A ]A$$$ Read consecutive 16-bit words in Hex, starting at address A ]A=n=n Write consecutive memory values, starting at address A ]40$$$ Reads CE data words 0x40, 0x41 and 0x42. ]7E=1AD2=9A23 Writes two hexadecimal words starting @ 0x7E ]10=+16384 Writes one decimal word starting @ 0x10 Example: Comment All CE data words are in 4-byte (32-bit) format. Typing ]A? will access the 32-bit word located at the byte address 0x0000 + 4 * A = 0x1028. Commands for MPU/XDATA Access: ) MPU DATA ACCESS Description: Allows user to read from and write to MPU data space. Usage: ) [Starting MPU Data Address] [option]…[option] Command combinations: )A??? Read three consecutive 32-bit words in Decimal, starting at address A )A$$$ Read three consecutive 32-bit words in Hex, starting at address A )A=n=m Write the values n and m to two consecutive addresses starting at address A ?) Display useful RAM addresses. )08$$$$ Reads data words 0x08, 0x0C, 0x10, 0x14 )04=FFFFAD2=9A23 Writes two hexadecimal words starting @ 0x04 )04=+1000 Writes decimal 1,000 to address 0x04 )04=-1000 Writes decimal -1,000 to address 0x04 Example: Comment MPU or XDATA space is the address range for the MPU XRAM (0x0000 to 0xFFF). All MPU data words are in 4-byte (32-bit) format. Typing ]A? will access the 32-bit word located at the byte address 4 * A = 0x28. The energy accumulation registers of the Demo Code can be accessed by typing two Dollar signs (“$$”), typing question marks will display negative decimal values if the most significant bit is set. 11 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual Commands for I/O RAM (Configuration RAM) and SFR Control: R I/O RAM AND SFR CONTROL Description: Allows the user to read from and write to DIO RAM and special function registers (SFRs). Usage: R [option] [register] … [option] Command combinations: RIx… Select I/O RAM location x (0x2000 offset is automatically added) Rx… Select internal SFR at address x Ra???... Read consecutive SFR registers in Decimal, starting at address a Ra$$$... Read consecutive registers in Hex, starting at address a Ra=n=m… Set values of consecutive registers to n and m starting at address a RI2$$$ Read DIO RAM registers 2, 3, and 4 in Hex. Example: Comment The SFRs (special function registers) are located in internal RAM of the 80515 core, starting at address 0x80. Commands for EEPROM Control: EE EEPROM CONTROL Description: Allows user to enable read from and write to EEPROM. Usage: EE [option] [arguments] Command combinations: EECn EEPROM Access (1  Enable, 0  Disable) EERa.b Read EEPROM at address 'a' for 'b' bytes. EESabc..xyz Write characters to buffer (sets Write length) EETa Transmit buffer to EEPROM at address 'a'. EEWa.b...z Write values to buffer CLS Saves calibration to EEPROM EEShello EET$0210 Writes 'hello' to buffer, then transmits buffer to EEPROM starting at address 0x210. Example: Comment Due to buffer size restrictions, the maximum number of bytes handled by the EEPROM command is 0x40. Commands for Flash Memory Control: F FLASH CONTROL Description: Allows user to enable read from and write to Flash memory. Usage: F [option] [arguments] Command combinations: FRa.b Read Flash at address 'a' for 'b' bytes. FSabc..xyz Write characters to buffer (sets Write length) FTa Transmit buffer to Flash memory at address 'a'. FWa.b...z Write string of bytes to buffer FShello FT$FE10 Writes 'hello' to buffer, then transmits buffer to EEPROM starting at address 0xFE10. Example: 12 Comment Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual Auxiliary Commands: Typing a comma (“,”) repeats the command issued from the previous command line. This is very helpful when examining the value at a certain address over time, such as the CE DRAM address for the temperature (0x40). The slash (“/”) is useful to separate comments from commands when sending macro text files via the serial interface. All characters in a line after the slash are ignored. Commands controlling the CE, TMUX and the RTM: C COMPUTE ENGINE, MEMORY, AND CALIBRATION CONTROL Description: Allows the user to enable and configure the compute engine, store and recall configurations, and initiate calibration. Usage: C [option] [argument] Command combinations: CEn Compute Engine Enable (1  Enable, 0  Disable) CTn.m Selects the signal for the TMUX output pins (n = 1 for TMUXOUT, n = 2 for TMUX2OUT). m is interpreted as a decimal number. CREn RTM output control (1  Enable, 0  Disable) CRSa.b.c.d Selects CE addresses for RTM output CLS Stores calibration and other settings to EEPROM. CLR Restores calibration and other settings from EEPROM. CLD Restores calibration and other settings to defaults. CLB Start auto-calibration based on voltage (MPU address 0x17, current (MPU 0x18), and duration (MPU 0x16) in seconds. CLC Apply machine-readable calibration control (Intel HexRecords). CPA Start the accumulating periodic pulse counters. CPC Clear the pulse counters CPDn Activate pulse counters for n seconds CE0 Disables CE, (“SYS will stop blinking on the LCD). CT1.3 Selects the VBIAS signal for the TMUX output pin Example: Comment Commands for Identification and Information: I INFORMATION MESSAGES Comment Description: Allows the user to read information messages. Usage: I Sends complete demo code version information on serial interface. M0 Displays meter ID on LCD. The I command is mainly used to identify the revisions of Demo Code and the contained CE code. 13 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual Commands for Battery Mode Control and Battery Test: B INFORMATION MESSAGES Comment Description: Allows the user to control battery modes and to test the battery. Usage: BL Enters LCD mode when in brownout mode (B> prompt). BS Enters sleep mode when in brownout mode (B> prompt). BT Starts a battery test – when in mission mode (> prompt). BWSn Set wake timer to n seconds for automatic return to brownout mode. BWMn Set wake timer to n minutes for automatic return to brownout mode. Commands for Controlling the RTC: RT REAL-TIME CLOCK CONTROL Description: Allows the user to read and set the real time clock. Usage: RT [option] [value] … [value] Command combinations: RTDy.m.d.w: Day of week (year, month, day, weekday [1 = Sunday]). If the weekday is omitted it is set automatically. RTR Read Real Time Clock. RTTh.m.s Time of day: (hr, min, sec). RTAs.t Real Time Adjust: (start, trim). Allows trimming of the RTC. If s > 0, the speed of the clock will be adjusted by ‘t’ parts per billion (PPB). If the CE is on, the value entered with 't' will be changing with temperature, based on Y_CAL, Y_CALC and Y_CALC2. > Access look-up table for RTC compensation. RTD05.03.17.5 Programs the RTC to Thursday, 3/17/2005 RTA1.+1234 Speeds up the RTC by 1234 PPB. >0???? Read the first four bytes in the look-up table. Example: Comment The “Military Time Format” is used for the RTC, i.e., 15:00 is 3:00 PM. Commands for Accessing the Trim Control Registers: T TRIM CONTROL Description: Allows user to read trim and fuse values. Usage: T [option] Command combinations: T4 Read fuse 4 (TRIMM). T5 Read fuse 5 (TRIMBGA) T6 Read fuse 6 (TRIMBGB). T4 Reads the TRIMM fuse. Example: Comment These commands are only accessible for the 71M6541H (0.1%) parts. When used on a 71M6541 (0.5%) part, the results will be displayed as zero. 14 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual Reset Commands: W RESET Description: Watchdog control Usage: W Comment Halts the Demo Code program, thus suppressing the triggering of the hardware watchdog timer. This will cause a reset, if the watchdog timer is enabled. Commands for the 71M6X0X Remote Sensor Interface: 15 6 71M6X0X Interface Comment Description: Commands for control of the Remote Sensor Interface IC. Usage: 6En Remote sensor Enable (1  Enable, 0  Disable) 6Ra.b Read Remote Sensor IC number a with command b. 6Ca.b Write command b to Remote Sensor IC number a. 6Ta.b Send command b to Remote Sensor IC number a in a loop forever. 6T2 Send temp command to 6000 number 2 in a loop forever. 6R1.20 Reads the temperature from Remote Sensor IC number 1. Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual Commands for Controlling the Metering Values Shown on the LCD Display: Step Text or Numerical Display CLI command 0 10000 00 M0 Meter ID 1 24.5 °C 01 M1 Temperature difference from calibration temperature. 2 59.9 02 M2 Frequency at the VA_IN input [Hz] 3 3.27 Whr 03 M3 Accumulated imported real energy [Wh]. The default display setting after power-up or reset. M4 Accumulated exported real energy [Wh]. M5 Accumulated reactive energy [VARh]. M6 Accumulated exported reactive energy [VARh]. M7 Accumulated apparent energy [VAh]. M8 Elapsed time since last reset or power up. M9 Time of day (hh.mm.ss) M10 Date (yy.mm.dd) 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 1.04 Whr 04 2.21 VARhr 05 0.95 VARhr 06 4.11 VAhr 07 0.7 hr 08 01:43:59 09 01.01.01 10 0.62 11 1 0 120 13 48 14 24.10 A 15 241.27 V 16 3.34 V 17 241.34 W 18 1 50400 W 19 88.88.88 88.88.88 88.88.88 Displayed Parameter(s) M11.P Power factor (P = phase) M12 Not used in the 71M6541 M13 Zero crossings of the mains voltage M14 Duration of sag or neutral current [s] M15.P RMS current (P = phase) M16 RMS voltage M17 Battery voltage M18 Momentary power in W (P = phase) M19 Demand M20 LCD Test Displays for total consumption wrap around at 999.999Wh (or VARh, VAh) due to the limited number of available display digits. Internal registers (counters) of the Demo Code are 64 bits wide and do not wrap around. 16 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 1.8.2 USING THE DEMO BOARD FOR ENERGY MEASUREMENTS The 71M6541 Demo Board was designed for use with shunt resistors connected directly to the IAP/IAN pins of the 71M6541 and via the Remote Sensor Interface and it is shipped in this configuration. The Demo Board may immediately be used with a 50 µΩ shunt resistor (ANSI) or a 120 µΩ shunt resistor (IEC). It is programmed for a kh factor of 1.0 (see Section 1.8.4 for adjusting the Demo Board for shunts with different resistance). Once, voltage is applied and load current is flowing, the red LED D5 will flash each time an energy sum of 1.0 Wh is collected. The LCD display will show the accumulated energy in Wh when set to display mode 3 (command >M3 via the serial interface). Similarly, the red LED D6 will flash each time an energy sum of 1.0 VARh is collected. The LCD display will show the accumulated energy in VARh when set to display mode 5 (command >M5 via the serial interface). 1.8.3 ADJUSTING THE KH FACTOR FOR THE DEMO BOARD The 71M6541F Demo Board is shipped with a pre-programmed scaling factor Kh of 1.0, i.e., 1.0 Wh per pulse. In order to be used with a calibrated load or a meter calibration system, the board should be connected to the AC power source using the spade terminals on the bottom of the board. The shunt resistor should be connected to the dual-pin header labeled J3 on the bottom of the board. The Kh value can be derived by reading the values for IMAX and VMAX (i.e., the RMS current and voltage values that correspond to the 250mV maximum input signal to the IC), and inserting them in the following equation for Kh: Kh = 109.1587*VMAX*IMAX / (SUM_SAMPS*WRATE*X), See the explanation in section 1.10.4 for an exact definition of the constants and variables involved in the equation above. 1.8.4 ADJUSTING THE DEMO BOARDS TO DIFFERENT SHUNT RESISTORS The Demo Board is prepared for use with 120 µΩ or 50 µΩ (ANSI option) shunt resistors in both current channels. For the Demo Board, a certain current flowing through the 120 µΩ shunt resistor will result in the maximum voltage drop at the ADC of the 71M6541. This current is defined as IMAX. IMAX will change when different values are used for the shunt resistor(s) which will require that WRATE has to be updated as shown in section 1.10.4. 1.8.5 USING THE PRE-AMPLIFIER In its default setting, the 71M6541 is applies a gain of 1 to the current input for phase A (IAP/IAN pins). This gain is controlled with the PRE_E bit in I/O RAM (refer to the IC data sheet). The command line interface (RI command) can be used to set or reset this bit. It is recommended to maintain the gain of setting of 1 (RI2704=0x90). 1.8.6 USING CURRENT TRANSFORMERS (CTs) Phase B of the 71M6541 Demo Board can be equipped with a CT that may be connected at header J8. A burden resistor of 1.7 Ω, or any other value may be installed at the R33 and R34 locations. With a 2000:1 ratio CT, the maximum current fort phase B will be 208 A. Note: The CT configuration will require a different version of the Demo Code. Current measurements can be displayed for phase B by the demo code, and the corresponding currents can be extracted by the MPU from the CE registers for tamper detection when using the Demo Code for EQU 0. 1.8.7 IMPLEMENTING A SINGLE-PHASE 3-WIRE METER (EQU 1) This application will require two identical current sensors for each phase. The simplest approach is to use identical shunt resistors for each channel. 1.8.8 ADJUSTING THE DEMO BOARDS TO DIFFERENT VOLTAGE-DIVIDERS The 71M6541 Demo Board comes equipped with its own network of resistor dividers for voltage measurement mounted on the PCB. The resistor values (for the D6541 REV 3.0 Demo Board) are 2.5477MΩ (R15-R21, R26R31 combined) and 750Ω (R32), resulting in a ratio of 1:3,393.933. This means that VMAX equals 176.78mV*3,393.933 = 600V. A large value for VMAX has been selected in order to have headroom for 17 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual overvoltages. This choice need not be of concern, since the ADC in the 71M6541 has enough resolution, even when operating at 120Vrms or 240Vrms. If a different set of voltage-dividers or an external voltage transformer (potential transformer) is to be used, scaling techniques should be used. In the following example we assume that the line voltage is not applied to the resistor divider for VA formed by R15-R21, R26-R31, and R32, but to a voltage transformer with a ratio N of 20:1, followed by a simple resistor divider. We also assume that we want to maintain the value for VMAX at 600V to provide headroom for large voltage excursions. When applying VMAX at the primary side of the transformer, the secondary voltage Vs is: Vs = VMAX / N Vs is scaled by the resistor divider ratio RR. When the input voltage to the voltage channel of the 71M6541 is the desired 177mV, Vs is then given by: Vs = RR * 177mV Resolving for RR, we get: RR = (VMAX / N) / 177mV = (600V / 30) / 177mV = 170.45 This divider ratio can be implemented, for example, with a combination of one 16.95 kΩ and one 100 Ω resistor. If potential transformers (PTs) are used instead of resistor dividers, phase shifts will be introduced that will require negative phase angle compensation. Maxim Integrated Demo Code accepts negative calibration factors for phase. 1.9 CALIBRATION PARAMETERS 1.9.1 GENERAL CALIBRATION PROCEDURE Any calibration method can be used with the 71M6541F chips. This Demo Board User’s Manual presents calibration methods with three or five measurements as recommended methods, because they work with most manual calibration systems based on counting "pulses" (emitted by LEDs on the meter). Naturally, a meter in mass production will be equipped with special calibration code offering capabilities beyond those of the 71M6541 Demo Code. It is basically possible to calibrate using voltage and current readings, with or without pulses involved. For this purpose, the MPU Demo Code can be modified to display averaged voltage and current values (as opposed to momentary values). Also, automated calibration equipment can communicate with the Demo Boards via the serial interface and extract voltage and current readings. This is possible even with the unmodified Demo Code. Complete calibration procedures are given in section 2.3 of this manual. Regardless of the calibration procedure used, parameters (calibration factors) will result that will have to be applied to the 71M6541F chip in order to make the chip apply the modified gains and phase shifts necessary for accurate operation. Table 1-4 shows the names of the calibration factors, their function, and their location in the CE RAM. Again, the command line interface can be used to store the calibration factors in their respective CE RAM addresses. For example, the command >]10=+16302 stores the decimal value 16302 in the CE RAM location controlling the gain of the current channel (CAL_IA). The command >]11=4005 stores the hexadecimal value 0x4005 (decimal 16389) in the CE RAM location controlling the gain of the voltage channel (CAL_VA). The internal power supply generates a ripple on the supply and ground nets that is 90° phase shifted with respect to the AC supply voltage. This affects the accuracy of the VARh measurements. If optimization of the VARh accuracy is required, this can be done by writing a value into the QUANT_VAR register of the CE (see section 2.3.7). 18 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual Table 1-4: CE RAM Locations for Calibration Constants Coefficient CE Address (hex) CAL_VA 0x11 Adjusts the gain of the voltage channels. +16384 is the typical value. The gain is directly proportional to the CAL parameter. Allowed range is 0 to 32767. If the gain is 1% slow, CAL should be increased by 1%. CAL_IA CAL_IB 0x10 0x13 Adjusts the gain of the current channels. +16384 is the typical value. The gain is directly proportional to the CAL parameter. Allowed range is 0 to 32767. If the gain is 1% slow, CAL should be increased by 1%. PHADJ_A LCOMP2_B 0x12 0x15 This constant controls the phase compensation. No compensation occurs in a phase when PHADJ_A = 0 or when LCOMP2_n = 16384. As LCOMP2_n is increased, more compensation is introduced. CE codes for CT configuration do not use delay adjustment. These codes use phase adjustment (PHADJ_n). Description 1.9.2 CALIBRATION MACRO FILE The macro file in Figure 1-4 contains a sequence of the serial interface commands. It is a simple text file and can be created with Notepad or an equivalent ASCII editor program. The file is executed with HyperTerminal’s Transfer->Send Text File command. CE0 ]10=+16022 ]11=+16381 ]12=+115 CE1 /disable CE /CAL_IA (gain=CAL_IA/16384) /CAL_VA (gain=CAL_VA/16384) /PHADJ_A (default 0) /enable CE Figure 1-4: Typical Calibration Macro File It is possible to send the calibration macro file to the 71M6541F for “temporary” calibration. This will temporarily change the CE data values. Upon power up, these values are refreshed back to the default values stored in flash memory. Thus, until the flash memory is updated, the macro file must be loaded each time the part is powered up. The macro file is run by sending it with the transfer  send text file procedure of HyperTerminal. Use the Transfer  Send Text File command! 1.9.3 UPDATING THE DEMO CODE (HEX FILE) The d_merge program updates the hex file (usually named 6541_1p2b_19jan09.hex or similar) with the values contained in the macro file. This program is executed from a DOS command line window. Executing the d_merge program with no arguments will display the syntax description. To merge macro.txt and old_6541_demo.hex into new_6541_demo.hex, use the command: d_merge old_6541_demo.hex macro.txt new_6541_demo.hex The new hex file can be written to the 71M6541F/71M6541H through the ICE port using the ADM-51 in-circuit emulator or the TFP-2 flash programmer. 19 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 1.9.4 UPDATING CALIBRATION DATA IN FLASH OR EEPROM It is possible to make data permanent that had been entered temporarily into the CE RAM. The transfer to EEPROM memory is done using the following serial interface command: >]CLS Thus, after transferring calibration data with manual serial interface commands or with a macro file, all that has to be done is invoking the U command. Similarly, calibration data can be restored to default values using the CLD command. After reset, calibration data is copied from the EEPROM, if present. Otherwise, calibration data is copied from the flash memory. Writing 0xFF into the first few bytes of the EEPROM deactivates any calibration data previously stored to the EEPROM. 1.9.5 LOADING THE CODE FOR THE 71M6541 INTO THE DEMO BOARD Hardware Interface for Programming: The 71M6541F IC provides an interface for loading code into the internal flash memory. This interface consists of the following signals: E_RXTX (data), E_TCLK (clock), E_RST (reset), ICE_E (ICE enable) These signals, along with V3P3D and GND are available on the emulator headers J14. Programming of the flash memory requires a specific in-circuit emulator, the ADM-51 by Signum Systems (www.signum.com) or the Flash Programmer (TFP2) available through Digi-Key (www.digikey.com) or Mouser Electronics (www.mouser.com). Chips may also be programmed before they are soldered to the board. Gang programmers suitable for highvolume production are available from BPM Microsystems (www.bpmmicro.com). In-Circuit Emulator: If firmware exists in the 71M6541F flash memory; it has to be erased before loading a new file into memory. Figure 1-5 and Figure 1-6 show the emulator software active. In order to erase the flash memory, the RESET button of the emulator software has to be clicked followed by the ERASE button. To successfully erase the flash memory, the following steps have to be taken: 1) Disable the CE by writing 0x00 to address 0x2000 2) Write 0x20 to address 0x2702 (FLSH_UNLOCK[ ] register in I/O RAM) 3) 4) 5) Reset the demo board (RESET button or power cycle) Activate the ERASE button in the WEMU51 user interface Now, new code can be loaded into the flash memory Once the flash memory is erased, the new file can be loaded using the commands File followed by Load. The dialog box shown in Figure 1-6 will then appear making it possible to select the file to be loaded by clicking the Browse button. Once the file is selected, pressing the OK button will load the file into the flash memory of the 71M6541F IC. At this point, the emulator probe (cable) can be removed. Once the 71M6541F IC is reset using the reset button on the Demo Board, the new code starts executing. 20 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual Figure 1-5: Emulator Window Showing Reset and Erase Buttons (see Arrows) Figure 1-6: Emulator Window Showing Erased Flash Memory and File Load Menu Flash Programmer Module (TFP-2): The operational firmware of the TFP2 will have to be upgraded to revision 1.53. Follow the instructions given in the User Manual for the TFP-2. 21 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 1.9.6 THE PROGRAMMING INTERFACE OF THE 71M6541 Flash Downloader/ICE Interface Signals The signals listed in Table 1-5 are necessary for communication between the Flash Downloader or ICE and the 71M6541. Signal ICE_E Direction Input to the 71M6541 E_TCLK E_RXTX E_RST Output from 71M6541 Bi-directional Bi-directional Function ICE interface is enabled when ICE_E is pulled high Data clock Data input/output Flash Downloader Reset (active low) Table 1-5: Flash Programming Interface Signals The E_RST signal should only be driven by the Flash Downloader when enabling these interface signals. The Flash Downloader must release E_RST at all other times. 22 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 1.10 DEMO CODE 1.10.1 DEMO CODE DESCRIPTION The Demo Board is shipped preloaded with Demo Code in the 71M6541F chip. The code revision can easily be verified by entering the command >i via the serial interface (see section 1.8.1). Check with your local Maxim Integrated representative or FAE for the latest revision. The Demo Code is provided in two different versions: • Single-phase two-wire operation (EQU 0, with secondary tamper sensor). Energy measurement and Wh/VARh pulses are based solely on VA (phase A voltage) and IA (phase A current). Energy and current values for IB (secondary phase) are available as CE outputs to the MPU for processing of tampering events. • Single-phase three-wire operation (ANSI configuration, EQU 1). Energy measurements and Wh/VARh pulses are based on VA (IA – IB) / 2. Both Demo Code versions use the same CE code, but with different settings of the EQU register. The Demo Code offers the following features: • It provides basic metering functions such as pulse generation, display of accumulated energy, frequency, date/time, and enables the user to evaluate the parameters of the metering IC such as accuracy, harmonic performance, etc. • It maintains and provides access to basic household functions such as the real-time clock (RTC). • It provides access to control and display functions via the serial interface, enabling the user to view and modify a variety of meter parameters such as Kh, calibration coefficients, temperature compensation etc. • It provides libraries for access of low-level IC functions to serve as building blocks for code development. A detailed description of the Demo Code can be found in the Software User’s Guide (SUG). In addition, the comments contained in the library provided with the Demo Kit can serve as useful documentation. The Software User’s Guide contains the following information: • Design guide • Design reference for routines • Tool Installation Guide • List of library functions • 80515 MPU Reference (hardware, instruction set, memory, registers) 1.10.2 IMPORTANT MPU ADDRESSES In the demo code, certain MPU XRAM parameters have been given addresses in order to permit easy external access. These variables can be read via the command line interface (if available), with the )n$ command and written with the )n=xx command where n is the word address. Note that accumulation variables are 64 bits long and are accessed with )n$$ (read) and )n=hh=ll (write) in the case of accumulation variables. The first part of the table, the addresses )00..)1F, contains adjustments, i.e., numbers that may need adjustment in a demonstration meter, and so are part of the calibration for demo code. In a reference meter, these may be in an unchanging table in code space. The second part, )20..)2F, pertains to calibration, i.e., variables that are likely to need individual adjustments for quality production meters. The third part, )30…, pertains to measurements, i.e., variables and registers that may need to be read in a demonstration meter. 23 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual Table 1-6: MPU XRAM Locations Name Purpose LSB Default )? Signed? Bits i_min Metering element enters creep mode if current is below this value. If 0, creep logic is disabled. In creep mode, on each metering element, Wh, VARh, i0sqsum, and other items are zeroed. Same units as CE’s i0sqsum. 0.08A )0 signed 32 )1 N/A 8 cfg Configure meter operation on the fly. bit0: 1=Display KWh. bit1: 1=clear accumulators, errors, etc. (e.g., “)1=2”) bit2: 1=Reset demand. (e.g., “)1=4”) bit3: 1=CE Raw mode. MPU does not change CE values with creep or small current calculations. bit5: 1= Send a message once per second for IEC 62056-217 Mode D on UART 1, at 2400 BAUD, even parity. The meter’s serial number and current Wh display are sent as data. UART 1 is routed to an IR LED if possible. Mode D data fields are prefaced with OBIS codes in legacy format. 7,1 bit6: 1=Auto calibration mode 1 bit7: 1=Enable Tamper Detect 0 Do nothing special. 2,1 v_min error if below. Also creep.* Below this, low voltage seconds are counted. Voltage, Wh, VARh, Frequency, and other voltage-dependent items are zeroed. Same units as CE’s v0sqsum. 40V )2 signed 32 )3 signed 16 i_max Scaling Maximum Amps for standard sensor. 0.1A 110.5 for 200 μΩ shunt with 8x preamp. 884.0 A for 200 μΩ shunt, 442.0A for 400 μΩ shunt. v_max Scaling Maximum Volts for PCB 0.1V 600 V, for the 6541 REV 3.0 Demo Board. )4 signed 16 i_limit Error if exceeded. Same units as CE’s i0sqsum. 50.9A = 30A*sqrt(2) *120% )5 signed 32 24 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual v_limit Error if exceeded.* Same units as CE’s v0sqsum. 407.3V = 240V*sqrt(2) *120% )6 signed 32 wrate_mpu Convert from CE counts to pulses. CE’s w0sum units per pulse, rounded up to next largest CE count so Wh accumulation and display is always rounded down. 3.2 Wh for 3phase 1.0 Wh for 1phase )7 signed 32 interval The number of minutes of a demand interval. Count of minutes. (60/interval)*interval = 60. 2 minutes. )8 unsigned 8 mains_hz Expected number of cycles per second of mains. 0 disables the software RTC run from mains. Hz 0 )9 unsigned 8 Refer to the IC data sheet. Temperature is calculated as temp = (measured_temp – temp_datum)/temp_cal1 + temp_cal0 Refer to the IC data sheet. )A signed 32 temp_cal1 Machine-readable units per 0.1C mtr_cal1 [0..3]9 Linear temperature calibration for meter elements A..D. ppm*(T - mtr_datum), in 0.1˚C 150 )B..E signed 16 mtr_cal2 [0..3]9 Squared temperature calibration for meter elements A..D. ppm2*(T - mtr_datum)2, in 0.1˚C -392 )F..1 2 signed 16 y_datum Center temperature of the crystal. 0.1C 25C )13 signed 16 RTC adjust, linear by temp. 10ppb*(T - y_datum), in 0.1˚C 0 )14 signed 16 RTC adjust, squared by temp. 1ppb*(T - y_datum)2, in 0.1˚C 38 )15 signed 16 Accumulation intervals of Autocalibration Count of accumulation intervals of calibration. accumulation intervals cover both chop polarities. )16 signed 16 Volts of Autocalibration 0.1V rms of AC signal applied to all elements during calibration. 2400 240 V is a standard fullscale setup for meter test. )17 signed 16 Amps of Autocalibration 0.1A rms of AC signal applied to all elements during calibration. Power factor of calibration signal must be 1. 300 30 A is a standard full-scale setup for meter test. )18 signed 16 y_cal1 5 y_cal2 5 s_cal v_cal i_cal 25 1 1 1 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual lcd_idx lcd_bit mfr_id 26 6 Selects LCD’s current display. 0: Meter identification. (“#”) 1: Display variation from calibration temperature, 0.1C 2: Display mains Hz, 0.1 Hz 3: mWh, total 4: mWh total exported. 5: mVARh, total. 6: mVARh, total exported. 7:mVAh, total 8: Operating hours. 9: Time of day 10: Calendar date 11: Power factor, total 12: Angle between phase 0 & 1 13: Main edge count, last accumulation. 14: KW, instantaneous total 15: V, instantaneous max of all phases. 16: A, total 17: V, Battery (“VB”) 18: Seconds, bad power (“BPS”) 19: Seconds, tamper (- = tamper in progress) (“TS”) 20: LCD Test Scrolling not standard for these: 111: PF, phase 0 112: Angle, phase 0 & 1 114: KW, phase 0 115: V, phase 0 116: A, phase 0 211: PF, phase 1 212: Angle, phase 0 & 2 214: KW, phase 1 215: V, phase 1 216: A, phase 1 311: PF, phase 2 312: Angle, phase 2.0 314: KW, phase 2 315: V, phase 2 316: A, phase 2 416: A, neutral (measured) 3 )19 signed 16 Defines sequence of LCD displays. The value is a bit mask that describes a scrolling display sequence. Each set bit permits a display with an lcd_idx value from 0..31. Each is displayed for 7 seconds. Ordered by increasing bit number. If value is zero, display does not change. 0 )1A unsigned 32 Manufacturer’s ID text string of the meter 3 ASCII bytes, in MSB of 32-bit number. Least significant byte should be zero. For AMR demonstrations, sent as the manufacturer’s ID of the meter. “TSC”, 0x54534300 )1B unsigned 32 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual i_max2 4 in_limit in_wait 3 3 Like i_max, except for the 2nd current sensor. Currents, Wh etc. using currents from the second sensor are rescaled into the same units as the first current sensor. 0.1 Amps 208 A (2080) )1C signed 16 Maximum valid neutral current. Same units as CE’s i3sqsum. 0.1A )1D signed 32 The time that neutral current can exceed n_max before the neutral error is asserted. Count of accumulation intervals. 10 secs. )1E signed 16 Reserved )1F Identification number of meter. 32 bit unsigned number. For AMR demonstrations, this is sent in decimal as the identification number of the meter. 100000000 )20 signed 32 Count of temperature sensor at calibration. Refer to the IC data sheet. Temperature is calculated as temp = (measured_temp – temp_datum)/temp_cal1 + temp_cal0 n/a )21 signed 32 Center temperature of a meter element’s temperature curve. 0.1C 22C )22.. 25 signed 16 Default value for RTCA_ADJ, the crystal’s capacitor adjustment. Refer to the IC data sheet. Set from hardware value when hardware is changed. Hardware default (refer to the IC data sheet). )26 unsigned 8 y_cal0 5,8 RTC offset rate adjust 100ppb 0 )27 signed 16 v_bat_min Minimum valid battery voltage. Units of hardware’s battery measurement register. 2V on a real PCB; should be adjusted for battery and chip. )28 signed 32 cal_cnt Count of calibrations. In demo code, it also checks adjustments. Counts number of times calibration is saved, to a maximum of 255. 0 )29 unsigned 8 ver_hash Checked to prevent old calibration data from being used by new code. Value that changes with the banner text, and therefore with the version, date and time. Uses data_ok() to calculate a value from the string. n/a )2A unsigned 8 data_ok_cal Checks calibrations. In demo code, it also checks adjustments. Checked by data_ok() of calibration value. n/a )2B unsigned 16 meter_id 8 temp_datum 8 mtr_datum[0. .3]8 rtca_adj Reserved 27 8 8 )2C. )2F Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual Status of meter. Nonvolatile. Bits: See table below. 0 = no errors )30 wh_im Wh energy register. Nonvolatile. First 32-bit number is a count of pulses, =3.2 Wh in 3-phase meters, or 1 in 1-phase. A fractional pulse is present in the CE data, but not preserved. n/a )31 64 wh_ex Wh exported energy register. Nonvolatile. Like wh_im n/a )32 64 varh_im VARh register. Nonvolatile. Like wh_im n/a )33 64 varh_ex VARh exported register. Nonvolatile. Like wh_im n/a )34 64 dmd_max Maximum demand, W Units of w0sum n/a )35 signed 32 dmd_max_rtc Time of maximum demand. Standard time and date structure. year, month, date, hour, min )36.. 3A unsigned 7x8 v_bat Battery voltage at last measurement. Volatile; not saved on power failure. 0.1V n/a )3B signed 8 acc_cnt Count of accumulation intervals since reset, or last clear. Cleared with )1=2 or meter read. Volatile; not saved on power failure. count n/a )3C signed 32 tamper_sec Counts seconds that tamper errors were asserted. Cleared with )1=2 or meter read. Nonvolatile. This is a tamper measurement. n/a )3D signed 32 sag_sec Counts seconds that voltage low error occurred. or meter read. Nonvolatile. This is a power quality measurement. n/a )3E signed 32 Counts seconds that neutral current error was asserted. Cleared with )1=2 or meter read. Nonvolatile. This is a power quality measurement. n/a )3F signed 32 rtc_copy Clock time and date when data was last read from the RTC. Standard time and date structure. year, month, date, hour, min, sec n/a )40.. 45 unsigned 8*7 save_cnt Number of power register saves. n/a n/a )46 unsigned 16 data_ok_reg Checks data. n/a n/a )47 unsigned 16 state_bit_ar y in_sec 3 unsigned 32 1 Valid only when autocalibration is integrated. Meters with metering equations with differential currents or voltages do not normally support autocalibration. 2 Requires features not in some demo PCBs. 28 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 3 Three-phase ICs only. Some CE codes calculate neutral current rather than measuring it. Consult the CE documentation. 4 Only in systems with two current sensors. 5 High accuracy use of this feature may require a calibrated clock. 6 IEC 62056 Manufacturers’ IDs are allocated by the FLAG Association Limited. Maxim Integrated does not own or profit from the FLAG association. Maxim Integrated’s default id may not conform, and is for demonstration purposes only. 7 Nothing in the document should be interpreted as a guarantee of conformance to a third-party software specification. Conformance testing is the responsibility of a meter manufacturer. 8 May require calibration for best accuracy. 9 Calibration item in high-precision “H” series meters (71M6541H only). Table 1-7: Bits in the MPU Status Word MINIA MINIB MINIC MINVA MINVB MINVC CREEPV CREEP SOFTWARE Bit No. 0 1 2 3 4 5 6 7 8 NEUTRAL SPURIOUS SAG DEMAND CALIBRATION 9 10 11 12 13 RTC_UNSET 14 HARDWARE 15 BATTERY_BAD 16 REGISTER_BAD 17 RTC_TAMPER TAMPER 18 19 Name Explanation IA is below IThrshld. Current for this phase is in creep. IB is below IThrshld. Current for this phase is in creep. IC is below IThrshld. Current for this phase is in creep. VA is below VThrshld. Voltage for this phase is in creep. VB is below VThrshld. Voltage for this phase is in creep. VC is below VThrshld. Voltage for this phase is in creep. All voltages are below VThrshld. There is no combination of current and voltage on any phase. A software defect was detected. error_software() was called. For example: An impossible value occurred in a selection, or the timers ran out. Neutral current was above in_limit for more than in_wait seconds. An unexpected interrupt was detected. Voltage was below VThrshld for more than in_wait seconds Demand was too big (too many watts) to be credible. Set after reset if the read of the calibration data has a bad checksum, or is from an earlier version of software. The default values should be present. Set when the clock’s current reading is A) Obtained after a cold start, indicating that there was no battery power, and therefore the clock has to be invalid. B) More than a year after the previously saved reading, or C) Earlier than the previously saved reading. In this case, the clock’s time is preserved, but the clock can’t be trusted. An impossible hardware condition was detected. For example, the software times out waiting for RTC_RD to become zero. Just after midnight, the demo code sets this bit if VBat < VBatMin. The read is infrequent to reduce battery loading to very low values. When the battery voltage is being displayed, the read occurs every second, for up to 20 seconds. Set after reset when the read of the power register data has a bad longitudinal redundancy check or bad software version in all 5 copies. Unlikely to be an accident. Clock set to a new value more than two hours from the previous value. Tamper was detected. Normally this is a power tamper detected in the creep logic. For example, current detected with no voltage. Table 1-8 contains LSB values for the CE registers used in the CE code for EQU 0 and EQU 1. All values are based on the following settings: • Gain in amplifier for IAP/IAN pins selected to 1. • 71M6103 or 71M6113 Remote Sensor Interface is used. Note that some of the register contents can be zeroed out by the MPU when it applies functions contained in its creep logic. 29 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 1.10.3 LSB VALUES IN CE REGISTERS Table 1-8: CE Registers and Associated LSB Values Register Name LSB Value W0SUM_X 1.55124*10-12*IMAX*VMAX VAR0SUM_X 1.55124*10-12*IMAX*VMAX W1SUM_X 1.55124*10-12*IMAX*VMAX VAR1SUM_X 1.55124*10-12*IMAX*VMAX I0SQSUM_X 2.55872*10-12*IMAX*VMAX I1SQSUM_X V0SQSUM_X 2.5587*10-12*IMAX*VMAX 9.40448*10-13*IMAX*VMAX V1SQSUM_X 9.40448*10-13*IMAX*VMAX Comment The real energy for element 1 (IA, VA), measured in Wh per accumulation interval The reactive energy for element 1 (IA, VA), measured in VARh per accumulation interval The real energy for element 2 (IB, VA), measured in Wh per accumulation interval The reactive energy for element 2 (IB, VA), measured in VARh per accumulation interval The sum of squared current samples in element 1 (IA). This value is the basis for the IRMS calculation performed in the MPU. The sum of squared current samples in element 2 (IB). This value is the basis for the IRMS calculation performed in the MPU. The sum of squared voltage samples in element 1 (VA). The sum of squared voltage samples in element 1 (VA). This value is not used for EQU 0 or EQU 1. 1.10.4 CALCULATING IMAX AND KH The relationship between the resistance of the shunt resistors and the system variable IMAX is determined by the type of Remote Sensor Interface used, and is as follows: IMAX = 0.044194 / RS for the 71M6601 IMAX = 0.012627 / RS for the 71M6201 Where: RS = Shunt resistance in Ω Table 1-9 shows IMAX values resulting from possible combinations of the shunt resistance value and the type of 71M6X0X Remote Sensor Interface used for the application. All values are for PRE_E = 0 (I/O RAM register 2704 = 0x90), PULSE_FAST = 0, and PULSE_SLOW = 0. The CE register at address 0x30 has to be adjusted as shown in the rightmost column of the table. 30 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual Table 1-9: IMAX for Various Shunt Resistance Values and Remote Sensor Types Remote Sensor Interface Rated Current [A] Max. Voltage at IAP/IAN [mV] 71M6601 60 62.5 71M6201 200 17.86 Shunt Resistor Value [µΩ] 500 400 300 250 200 160 120 75 50 25 88.39 110.49 147.31 176.78 220.97 276.21 368.28 IMAX Entry at MPU 0x03 +884 +1105 +1473 +1768 +2209 +2762 +3683 WRATE for kH = 1.0 and VMAX = 600 V 383 497 638 766 957 1196 1595 CE address 0x30 2483 2483 2483 2483 2483 2483 2483 168.4 252.6 505.1 +1684 +2526 +5051 729 1094 2188 8691 8691 8691 IMAX [A] The meter constant kh (Wh per pulse) is calculated as follows: Kh = 109.1587*VMAX*IMAX / (SUM_SAMPS*WRATE*X), where VMAX = RMS voltage at the meter input corresponding to 176.8 mV RMS at the VA pin of the 71M6541. This value is determines by the divider ratio of the voltage-divider resistors. For the 71M6541 Demo Board, this value is 600. IMAX = RMS current through one current sensor corresponding to 176.8 mV RMS at the IAP/IAN or IBP/IBN pins of the 71M6541, as determined by the formula above. Note: For the IBP/IBN pins, no physical analog voltage exists due to the digital nature of the current measurement via the remote interface. SUM_SAMPS = The value in the SUM_SAMPS register in I/O RAM (2520 for this version of the Demo Code). WRATE = The value in the pulse rate adjustment register of the CE. X = The pulse rate adjustment modifier, determined by the PULSE_FAST and PULSE_SLOW bits in the CECONFIG register. A kh of 1 (1.00 Wh per pulse) is achieved by the following combination of system settings: VMAX = 600 V IMAX = 368.3 A, based on RS = 120 μΩ SUM_SAMPS = 2520 WRATE = 1595, based on X = 6, and PULSE_FAST = 0 and PULSE_SLOW = 0 1.10.5 DETERMINING THE TYPE OF 71M6X0X Sometimes it is useful to be able to determine the type of 71M6X0X Remote Sensor Interface that is mounted on the Demo Board. The CLI can be used to find out which 71M6X0X Remote Sensor Interface is present, using the following steps: 31 1) Type 6R1.14 at the command prompt (>). 2) The CLI will respond with a two-byte hex value, e.g., E9DB. 3) Write the hex value out as binary sequence, e.g., 1110 1001 1101 1011. Bits 4 and 5 determine the type of the 71M6X0X Remote Sensor Interface, as shown in Table 1-10. Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual Table 1-10: Identification of 71M6X0X Remote Sensor Types Bit 5/Bit 4 71M6X0X Remote Interface Current Range [A] 00 71M6601 or 71M6603 60 01 71M6103 or 71M6113 (Poly-Phase) 100 10 71M6201 or 71M6203 200 11 Invalid -- 1.10.6 COMMUNICATING WITH THE 71M6X0X Some commands are useful to communicate with the 71M6X0X Remote Sensor Interface for the purpose of test and diagnosis. Some useful commands are: 1) 6C1.42 – this command causes the 71M6X0X Remote Sensor Interface to output its reference voltage on the TMUX pin (pin 5). 2) 6R1.20 – this command returns the reading from the temperature sensor (STEMP) of the 71M6X0X Remote Sensor Interface in a two-byte hexadecimal format (e.g., FFDF). Negative readings are signaled by the MSB being 1. 2 T = 22°C + (STEMP*0.337 - (STEMP )*0.00015)°C Example: For STEMP = 0xFFDF the decimal equivalent is -32. The temperature calculates to 22°C – 10.9°C = 11.1°C. Note that the IC temperature is averaged and displayed more accurately with the M1 command. 1.10.7 BOOTLOADER FEATURE Demo Codes 5.4F and later are equipped with a bootloader feature. This feature allows the loading of code via the serial interface (USB connector CN1) when a Signum ADM-51 emulator or the Maxim Integrated TFP2 Flash Loader is not available. The bootloader functions as follows: 1) Meter code must be modified in order to be loaded by the bootloader. The meter code must start at address 0x0400, and its interrupt vector table must also start at 0x400. The bootloader itself is located at address 0x0000 and must be loaded into the IC by some method if the flash memory of the 71M6543 is empty or if code of a previous revision is loaded. The bootloader is part of Demo Code 5.4F. 2) The bootloader loads Intel hex-86 files at 38,400 baud 8 bits, no parity. It will only accept record types 0, 4 and 1, which are the types produced by Maxim Integrated’s bank_merge program or checksum program, and the Keil compiler (PK51). No records may overlap. (Keil, bank_merge and checksum produce this style of hex file by default.) The records from 0x00000 to 0x00400 are ignored, so that the bootloader can't overwrite itself. 3) If the bootloader load process is not invoked, the bootloader jumps to address 0x0400 and executes the code found there. 4) A detailed description of the bootloader can be found in the _readme.txt file contained in the source code ZIP package. For a 71M6541-DB containing code with the bootloader, instructions for loading new code are as follows: 32 1) Connect a PC running HyperTerminal or a similar terminal program to the DB6543. Set the program to 38,400 baud 8 bits, no parity, XON/XOFF flow control. 2) Turn off the power to the 71M6541-DB. 3) Install a jumper from board ground to the VARh pulse output (JP59, right pin), which is also SEGDIO1. A low voltage on this pin signals to the bootloader that new code should be loaded via the UART. 4) Apply power to the meter. 5) After a brief delay, the Wh pulse LED (D5) will light up (SEGDIO0). The bootloader should send a ":" on the UART to the PC. If this occurs, the flash is erased, and the 71M6541-DB is ready to load code. - If this does not occur, check the jumper, and reset or repower the unit - If the Wh LED still does not light up, then the boot code is not installed. - If the Wh LED lights up, but the ":" does not appear, debug the RS-232 wiring. Possible issues are that the baud rate is not 38400 baud, or that the wiring is wrong, (debug using a known-good meter), or that the terminal program in the PC is not working. Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 33 6) Send the Intel hex file built for operation with the bootloader (e.g., 6541eq0_5p4g_07feb12.hex) using the ‘Send Text File’ command of HyperTerminal. 7) During the load procedure, the Wh LED will blink. Once the load process is completed it stops blinking. The Wh LED should remain on solidly at the completion of the load procedure, which indicates an error-free load. If the LED turns off at the end, an error must have occurred. In this case the load should be repeated. The bootloader sends a "1" on the UART if the load succeeded, and "0" if it failed. 8) Check the display of terminal program (e.g., the PC running Hyperterminal). If no checksum error has occurred, the bootloader sends a 1 on the UART. In case of an error, reset the DB6543, or turn it off and on, and reload the code. 9) Remove the jumper on JP7. This will cause the loaded Demo Code to start. Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 2 2 APPLICATION INFORMATION 2.1 SENSOR CONNECTIONS AND EQUATIONS The 71M6541 Demo Board supports the following meter configurations and equations: • Single-phase two-wire (EQU 0) • Single-phase three-wire (EQU 1) Note: Support of EQU 2 requires the 71M6542 IC, which will be available on a separate Demo Board. CAUTION: THE DIAGRAMS SHOWN IN THIS SECTION ARE SYMBOLIC AND DO NOT REFLECT THE PHYSICAL CONNECTIONS OF THE DEMO BOARD! THE GROUND OF THE DEMO BOARD IS AT LINE (LIVE) VOLTAGE! 2.1.1 SENSOR WIRING The Demo Board is referenced to LINE voltage. This means that the sensor wires have to be connected as shown in Figure 2-1. Shunt LINE LOAD Neutral LINE NEUTRAL IAN IAP Figure 2-1: Shunt Connections 34 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 2.1.2 SINGLE-PHASE TWO-WIRE (EQU 0) This is the most basic configuration for this Demo Board. The current sensor is connected directly to the IAP/IAN inputs of the 71M6541 (see Figure 2-2). The energy measurement is based on the following equation: P = VA * IA See the explanation below Table 1-8 for the calculation of IMAX. A second current sensor can be connected to the IBP/IBP inputs of the 71M6541, for example to detect tampering (see Figure 2-3). The second current sensor can be another shunt resistor that is isolated using the onboard 71M6X0X Remote Sensor Interface. The Demo Board has provisions for connecting either a shunt or a CT sensor, but the default configuration is the shunt sensor connected via on-board 71M6X0X Remote Sensor Interface. See section 3.1 for details. Shunt LINE LOAD N Distribution transformer 71M6541 IAP IAN V3P3A VA Figure 2-2: Single-Phase Two-Wire Meter with Shunt Sensor Shunt LINE N LOAD Shunt 71M6XXX 71M6541 IAP IAN IBP IBN VA V3P3A Figure 2-3: Single-Phase Two-Wire Meter with two Shunt Sensors When the Demo Code is using equation 0, the energy calculation and pulse generation is solely based on the primary shunt (IAP/IAN). The readings from the second shunt can be obtained by the MPU in CE registers and used for tamper detection. Since the shunt in the second current channel may be different from the shunt used 35 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual in the primary channel, the CE code allows scaling between the two channels so that all energy calculations can be based on IMAX. 2.1.3 SINGLE-PHASE THREE-WIRE (EQU 1) This meter configuration (see Figure 2-4) is used in North America (ANSI market) and parts of South America. The energy measurement is based on the following equation: P = VA/2 * (IA – IB) Both current sensors can be shunt sensors. The second current sensor may also be a CT. The Demo Board has provisions for connecting either sensor type, but the default configuration for the second current sensor is the connection via on-board 71M6X0X Remote Sensor Interface. Distribution transformer Shunt A LOAD A N B LOAD LOAD B Shunt 71MXXXX 71M65XX IAP IAN VA IBP IBN V3P3A Figure 2-4: Single-Phase Three-Wire Meter with two Shunt Sensors By default, the gain of the amplifier for the IAP/IAN inputs is set to 1. See the explanation below Table 1-8 for the calculation of IMAX. As for the single-phase two-wire configuration, the CE code allows for scaling of differences between the currents in both phases so that all energy calculations can be based on IMAX. 36 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 2.2 CALIBRATION THEORY A typical meter has phase and gain errors as shown by φS, AXI, and AXV in Figure 2-5. Following the typical meter convention of current phase being in the lag direction, the small amount of phase lead in a typical current sensor is represented as -φS. The errors shown in Figure 2-5 represent the sum of all gain and phase errors. They include errors in voltage attenuators, current sensors, and in ADC gains. In other words, no errors are made in the ‘input’ or ‘meter’ boxes. INPUT I ERRORS φL −φS φ L is phase lag METER IRMS A XI IDEAL = I , φS is phase lead Π V W V RMS AXV ERROR ≡ ACTUAL = I AXI IDEAL = IV cos(φ L ) ACTUAL = IV AXI AXV cos(φ L − φ S ) IDEAL = V , ACTUAL = V AXV ACTUAL − IDEAL = ACTUAL − 1 IDEAL IDEAL Figure 2-5: Watt Meter with Gain and Phase Errors. During the calibration phase, we measure errors and then introduce correction factors to nullify their effect. With three unknowns to determine, we must make at least three measurements. If we make more measurements, we can average the results and get better accuracy. 2.2.1 CALIBRATION WITH THREE MEASUREMENTS The simplest calibration method is to make three measurements. Typically, a voltage measurement and two Watt-hour (Wh) measurements are made. A voltage display can be obtained for test purposes via the command >MR2.1 in the serial interface. Let’s say the voltage measurement has the error EV and the two Wh measurements have errors E0 and E60, where E0 is measured with φL = 0 and E60 is measured with φL = 60. These values should be simple ratios—not percentage values. They should be zero when the meter is accurate and negative when the meter runs slow. The fundamental frequency is f0. T is equal to 1/fS, where fS is the sample frequency (2560.62Hz). Set all calibration factors to nominal: CAL_IA = 16384, CAL_VA = 16384, PHADJA = 0. Note: In the formulae used in this section, the register /variable name PHADJA is used. The CE code for the 71M6541 in reality uses a more advanced type of compensation that results in a delay adjust. The register name for this compensation factor is DLYADJ_A. For the purpose of the calculation, the two names are interchangeable. From the voltage measurement, we determine that 1. AXV = EV + 1 We use the other two measurements to determine φS and AXI. 37 IV AXV AXI cos(0 − φ S ) − 1 = AXV AXI cos(φ S ) − 1 IV cos(0) 2. E0 = 2a. AXV AXI = 3. E 60 = E0 + 1 cos(φ S ) IV AXV AXI cos(60 − φ S ) cos(60 − φ S ) − 1 = AXV AXI −1 IV cos(60) cos(60) Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 3a. AXV AXI [cos(60) cos(φ S ) + sin(60) sin(φ S )] −1 cos(60) E 60 = = AXV AXI cos(φ S ) + AXV AXI tan(60) sin(φ S ) − 1 Combining 2a and 3a: 4. E 60 = E 0 + ( E 0 + 1) tan(60) tan(φ S ) 5. tan(φ S ) = 6. φ S = tan −1  E 60 − E 0 ( E 0 + 1) tan(60)   E 60 − E 0   ( E 0 + 1) tan(60)  and from 2a: 7. E0 + 1 AXV cos(φ S ) AXI = Now that we know the AXV, AXI, and φS errors, we calculate the new calibration voltage gain coefficient from the previous ones: CAL _ V NEW = CAL _ V AXV We calculate PHADJ from φS, the desired phase lag: [ ]   tan(φ S ) 1 + (1 − 2 −9 ) 2 − 2(1 − 2 −9 ) cos(2πf 0T ) PHADJ = 2 20   −9 −9  (1 − 2 ) sin( 2πf 0T ) − tan(φ S ) 1 − (1 − 2 ) cos(2πf 0T )  [ ] And we calculate the new calibration current gain coefficient, including compensation for a slight gain increase in the phase calibration circuit. CAL _ I NEW = CAL _ I AXI 1 1+ 2 − 20 PHADJ (2 + 2 − 20 PHADJ − 2(1 − 2 −9 ) cos(2πf 0T )) 1 − 2(1 − 2 −9 ) cos(2πf 0T ) + (1 − 2 −9 ) 2 2.2.2 CALIBRATION WITH FIVE MEASUREMENTS The five measurement method provides more orthogonality between the gain and phase error derivations. This method involves measuring EV, E0, E180, E60, and E300. Again, set all calibration factors to nominal, i.e., CAL_IA = 16384, CAL_VA = 16384, PHADJA = 0. First, calculate AXV from EV: 1. AXV = EV + 1 Calculate AXI from E0 and E180: 38 IV AXV AXI cos(0 − φ S ) − 1 = AXV AXI cos(φ S ) − 1 IV cos(0) 2. E0 = 3. E180 = 4. E 0 + E180 = 2 AXV AXI cos(φ S ) − 2 IV AXV AXI cos(180 − φ S ) − 1 = AXV AXI cos(φ S ) − 1 IV cos(180) Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 5. AXV AXI = 6. AXI = E 0 + E180 + 2 2 cos(φ S ) ( E 0 + E180 ) 2 + 1 AXV cos(φ S ) Use above results along with E60 and E300 to calculate φS. 7. E 60 = IV AXV AXI cos(60 − φ S ) −1 IV cos(60) = AXV AXI cos(φ S ) + AXV AXI tan(60) sin(φ S ) − 1 8. E300 = IV AXV AXI cos(−60 − φ S ) −1 IV cos(−60) = AXV AXI cos(φ S ) − AXV AXI tan(60) sin(φ S ) − 1 Subtract 8 from 7 9. E 60 − E300 = 2 AXV AXI tan(60) sin(φ S ) use equation 5: E 0 + E180 + 2 tan(60) sin(φ S ) cos(φ S ) 10. E 60 − E300 = 11. E 60 − E300 = ( E 0 + E180 + 2) tan(60) tan(φ S ) 12. φ S = tan −1    ( E 60 − E300 )  + + tan( 60 )( E E 2 ) 0 180   Now that we know the AXV, AXI, and φS errors, we calculate the new calibration voltage gain coefficient from the previous ones: CAL _ V NEW = CAL _ V AXV We calculate PHADJ from φS, the desired phase lag: [ ]   tan(φ S ) 1 + (1 − 2 −9 ) 2 − 2(1 − 2 −9 ) cos(2πf 0T ) PHADJ = 2   −9 −9  (1 − 2 ) sin( 2πf 0T ) − tan(φ S ) 1 − (1 − 2 ) cos(2πf 0T )  20 [ ] And we calculate the new calibration current gain coefficient, including compensation for a slight gain increase in the phase calibration circuit. CAL _ I NEW = 39 CAL _ I AXI 1 1+ 2 − 20 PHADJ (2 + 2 PHADJ − 2(1 − 2 −9 ) cos(2πf 0T )) 1 − 2(1 − 2 −9 ) cos(2πf 0T ) + (1 − 2 −9 ) 2 − 20 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 2.3 CALIBRATION PROCEDURES 2.3.1 CALIBRATION EQUIPMENT Calibration requires that a calibration system is used, i.e., equipment that applies accurate voltage, load current and load angle to the unit being calibrated, while measuring the response from the unit being calibrated in a repeatable way. By repeatable we mean that the calibration system is synchronized to the meter being calibrated. Best results are achieved when the first pulse from the meter opens the measurement window of the calibration system. This mode of operation is opposed to a calibrator that opens the measurement window at random time and that therefore may or may not catch certain pulses emitted by the meter. It is essential for a valid meter calibration to have the voltage stabilized a few seconds before the current is applied. This enables the Demo Code to initialize the 71M6541F and to stabilize the PLLs and filters in the CE. This method of operation is consistent with meter applications in the field as well as with metering standards. During calibration of any phase, a stable mains voltage has to be present on phase A. This enables the CE processing mechanism of the 71M6541F necessary to obtain a stable calibration. 2.3.2 PHASE-BY-PHASE CALIBRATION Each meter phase must be calibrated individually. Some calibration systems do not allow selective control of currents in each phase. Each phase can still be individually calibrated using the following sequence: • When calibrating phase A, the calibration coefficient for the current in phase B is set to zero. This way, the pulses are generated solely based on phase A. The kH factor of the calibration system must be adjusted by -50% to account for the suppression of 50% of the energy. • When calibrating phase B, the calibration coefficient for the current in phase A is set to zero. This way, the pulses are generated solely based on phase B. The kH factor of the calibration system must be adjusted by -50% to account for the suppression of 50% of the energy. • For the final step, both current calibration coefficients are set to their calibration values and the meter can be tested at the original kH setting. 2.3.3 DETAILED CALIBRATION PROCEDURES The procedures below show how to calibrate a meter phase with either three or five measurements. The PHADJ equations apply only when a current transformer is used for the phase in question. Note that positive load angles correspond to lagging current (see Figure 2-6). Voltage Positive direction Current lags voltage (inductive) +60° Current -60° Current leads voltage (capacitive) Voltage Generating Energy Using Energy Figure 2-6: Phase Angle Definitions 40 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual The calibration procedures described below should be followed after interfacing the voltage and current sensors to the 71M6541F chip. When properly interfaced, the V3P3 power supply is connected to the meter neutral and is the DC reference for each input. Each voltage and current waveform, as seen by the 71M6541F, is scaled to be less than 250mV (peak). 2.3.4 CALIBRATION PROCEDURE WITH THREE MEASUREMENTS Each phase is calibrated individually. The calibration procedure is as follows: 1) The calibration factors for all phases are reset to their default values, i.e., CAL_In = CAL_Vn = 16384, and PHADJ_n = 0. 2) An RMS voltage Videal consistent with the meter’s nominal voltage is applied, and the RMS reading Vactual of the meter is recorded. The voltage reading error Axv is determined as Axv = (Vactual - Videal ) / Videal 3) Apply the nominal load current at phase angles 0° and 60°, measure the Wh energy and record the errors E0 AND E60. 4) Calculate the new calibration factors CAL_In, CAL_Vn, and PHADJ_n, using the formulae presented in section 2.2.1 or using the spreadsheet presented in section 2.3.6. 5) Apply the new calibration factors CAL_In, CAL_Vn, and PHADJ_n to the meter. The memory locations for these factors are given in section 1.9.1. 6) Test the meter at nominal current and, if desired, at lower and higher currents and various phase angles to confirm the desired accuracy. 7) Store the new calibration factors CAL_In, CAL_Vn, and PHADJ_n in the EEPROM or FLASH memory of the meter. If the calibration is performed on a Maxim Integrated Demo Board, the methods involving the command line interface, as shown in sections 1.9.3 and 1.9.4, can be used. 8) Repeat the steps 1 through 7 for each phase. 9) For added temperature compensation, read the value TEMP_RAW (CE RAM) and write it to TEMP_NOM (CE RAM). If Demo Code 4.6n or later is used, this will automatically calculate the correction coefficients PPMC and PPMC2 from the nominal temperature and from the characterization data contained in the on-chip fuses. Tip: Step 2 and the energy measurement at 0° of step 3 can be combined into one step. 41 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 2.3.5 CALIBRATION PROCEDURE WITH FIVE MEASUREMENTS Each phase is calibrated individually. The calibration procedure is as follows: 1) The calibration factors for all phases are reset to their default values, i.e., CAL_In = CAL_Vn = 16384, and PHADJ_n = 0. 2) An RMS voltage Videal consistent with the meter’s nominal voltage is applied, and the RMS reading Vactual of the meter is recorded. The voltage reading error Axv is determined as Axv = (Vactual - Videal ) / Videal 3) Apply the nominal load current at phase angles 0°, 60°, 180° and –60° (-300°). Measure the Wh energy each time and record the errors E0, E60, E180, and E300. 4) Calculate the new calibration factors CAL_In, CAL_Vn, and PHADJ_n, using the formulae presented in section 2.2.2 or using the spreadsheet presented in section 2.3.6. 5) Apply the new calibration factors CAL_In, CAL_Vn, and PHADJ_n to the meter. The memory locations for these factors are given in section 1.9.1. 6) Test the meter at nominal current and, if desired, at lower and higher currents and various phase angles to confirm the desired accuracy. 7) Store the new calibration factors CAL_In, CAL_Vn, and PHADJ_n in the EEPROM or FLASH memory of the meter. If a Demo Board is calibrated, the methods involving the command line interface shown in sections 1.9.3 and 1.9.4 can be used. 8) Repeat the steps 1 through 7 for each phase. 9) For added temperature compensation, read the value TEMP_RAW (CE RAM) and write it to TEMP_NOM (CE RAM). If Demo Code 4.6n or later is used, this will automatically calculate the correction coefficients PPMC and PPMC2 from the nominal temperature and from the characterization data contained in the on-chip fuses. Tip: Step 2 and the energy measurement at 0° of step 3 can be combined into one step. 2.3.6 CALIBRATION SPREADSHEETS Calibration spreadsheets are available from Maxim Integrated. Figure 2-7 shows the spreadsheet for three measurements. Figure 2-8 shows the spreadsheet for five measurements with three phases. Different tabs are to be used for equation 0/2 and equation 1. For the calibration, data should be entered into the calibration spreadsheets as follows: 42 1. Calibration is performed one phase at a time. 2. Results from measurements are generally entered in the yellow fields. Intermediate results and calibration factors will show in the green fields. 3. The line frequency used (50 or 60Hz0 is entered in the yellow field labeled AC frequency. 4. After the voltage measurement, measured (observed) and expected (actually applied) voltages are entered in the yellow fields labeled “Expected Voltage” and “Measured Voltage”. The error for the voltage measurement will then show in the green field above the two voltage entries. 5. The relative error from the energy measurements at 0° and 60° are entered in the yellow fields labeled “Energy reading at 0°” and “Energy reading at 60°”. The corresponding error, expressed as a fraction will then show in the two green fields to the right of the energy reading fields. 6. The spreadsheet will calculate the calibration factors CAL_IA, CAL_VA, and PHADJ_A from the information entered so far and display them in the green fields in the column underneath the label “new”. 7. If the calibration was performed on a meter with non-default calibration factors, these factors can be entered in the yellow fields in the column underneath the label “old”. For a meter with default calibration factors, the entries in the column underneath “old” should be at the default value (16384). Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual Figure 2-7: Calibration Spreadsheet for Three Measurements 43 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual Figure 2-8: Calibration Spreadsheet for Five Measurements 44 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 2.3.7 COMPENSATING FOR NON-LINEARITIES Nonlinearity is most noticeable at low currents, as shown in Figure 2-9, and can result from input noise and truncation. Nonlinearities can be eliminated using the QUANT variable. 12 error [%] 10 error 8 6 4 2 0 0.1 1 10 100 I [A] Figure 2-9: Non-Linearity Caused by Quantification Noise The error can be seen as the presence of a virtual constant noise current. While 10mA hardly contribute any error at currents of 10A and above, the noise becomes dominant at small currents. The value to be used for QUANT can be determined by the following formula: error V ⋅I 100 QUANT = − VMAX ⋅ IMAX ⋅ LSB Where error = observed error at a given voltage (V) and current (I), VMAX = voltage scaling factor, as described in section 1.8.3, IMAX = current scaling factor, as described in section 1.8.3, LSB = QUANT LSB value = 7.4162*10-10W Note that different values for the LSB of QUANT apply, depending on which type of code is used. The LSB values are listed in the IC data sheet for standard CE codes. Example: Assuming an observed error for a meter with local sensors as in Figure 2-9, we determine the error at 1A to be +0.5%. If VMAX is 600V and IMAX = 208A, and if the measurement was taken at 240V, we determine QUANT as follows: QUANT LSB = 1.04173*10-9 VMAX IMAX = 1.3*10-4 0.5 240 ⋅1 QUANT = − 100 = −9230 QUANT _ LSB QUANT is to be written to the CE location given by the IC data sheet. It does not matter which current value is chosen as long as the corresponding error value is significant (1% error at 1.0 A used in the above equation will produce the same result for QUANT). Input noise and truncation can cause similar errors in the VAR calculation that can be eliminated using the QUANT_VAR variable. QUANT_VAR is determined using the same formula as QUANT. The internal power supply generates a ripple on the supply and ground nets that is 90° phase shifted with respect to the AC supply voltage. This affects the accuracy of the VARh measurements. If optimization of the VARh accuracy is required, this can be done by writing a value into the QUANT_VAR register of the CE 45 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 2.4 TEMPERATURE COMPENSATION 2.4.1 ERROR SOURCES For a meter to be accurate over temperature, the following major sources of error have to be addressed: 1) The resistance of the shunt sensor(s) over temperature. The temperature coefficient (TC) of a shunt resistor is typically positive (PTC) and can be far higher than the TC of the pure Manganin material used in the shunt. TCs of several hundred PPM/°C have been observed for certain shunt resistors. A -6 shunt resistor with +100 PPM/°C will increase its resistance by 60°C * 100*10 PPM/°C, or +0.6% when heated up from room temperature to +85°C, causing a relative error of +0.6% in the current reading. This makes the shunt the most pronounced influence on the temperature characteristics of the meter. Typically, the TC of shunt resistors is linear over the industrial temperature range and can be compensated granted the shunt resistor is at the same temperature as the on-chip temperature sensors on the 71M6X0X Remote Sensor Interface IC or the 71M6541. Generally, the lower the TC of a shunt resistor, the better it can be compensated. Shunts with high TCs require more accurate temperature measurements than those with low TCs. For example, if a shunt with 200 PPM/°C is used, and the temperature sensor available to the 71M6543 is only accurate to ±3°C, the compensation can be inaccurate by as much as 3°C*200PPM/°C = 600 PPM, or 0.06%. 2) The reference voltage of the 71M6X0X Remote Sensor Interface IC. At the temperature extremes, this voltage can deviate by a few mV from the room temperature voltage and can therefore contribute to some temperature-related error. The TC of the reference voltage has both linear and quadratic components (TC1 and TC2). Since the 71M6X0X Remote Interface IC has an on-chip temperature sensor, and since the development of the reference voltage over temperature is predictable to within ±40 PPM/°C, compensation of the current reading is possible to within ±60°C *40*10-6 PPM/°C, or ±0.24%. The reference voltage can be approached by the nominal reference voltage: 2 VNOM(T) = VNOM(22)+(T-22)*TC1+(T-22) *TC2 Actual values for TC1 and TC2 can be obtained as follows: TC1 = 3.50*10-4 - 6.04*10-6 * TRIMT and TC2 = -8.11*10-7 + 4.19*10-9 * TRIMT The TRIMT value can be read from the 71M6X0X Remote Sensor Interface IC. 3) The reference voltage of the 71M6541 IC. At the temperature extremes, this voltage can deviate by a few mV from the room temperature voltage and can therefore contribute to some temperature-related error, both for the current measurement (pins IAP and IAN) of the secondary shunt sensor and for the voltage measurement (pin VA). As with the Remote Sensor Interface IC, the TC of the 71M6541 reference voltage has both linear and quadratic components. The reference voltage of the 71M6541 over temperature is predictable within ±40 PPM/°C, which means that compensation of the current and voltage reading is possible to within ±0.24%. The temperature coefficients of the reference voltage are published in the IC data sheet. 4) The voltage-divider network (resistor ladder) on the Demo Board will also have a TC. Ideally, all resistors of this network are of the same type so that temperature deviations are balanced out. However, even in the best circumstances, there will be a residual TC from these components. The error sources for a meter are summed up in Table 2-1. Table 2-1: Temperature-Related Error Sources Measured Item Error Sources for Current Error Sources for Voltage Energy reading in direct channel VA and (IAP/IAN) 71M6541 VREF 71M6541 VREF Energy Reading in remote channel VA and (IBP/IBN) 46 Shunt resistor at IAP/IAN Voltage-divider for VA VREF of 71M6XX1 Remote Sensor IC 71M6541 VREF Shunt resistor at Remote Interface IC Voltage-divider for VA Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual When analyzing the contribution of thermal errors for power equation 1 for single-phase 3-wire systems, we can write the equation as follows: P = VA ( IA − IB) VA ⋅ CVD ⋅ C4 X ⋅ IA ⋅ C S 1 ⋅ C4 X VA ⋅ CVD ⋅ C4 X ⋅ IB ⋅ C S 2 ⋅ C6 X ) = − 2 2 2 The terms used in the above equation are defined as follows: • VA = voltage applied to the meter • IA = current applied to the shunt S1 that is connected to the IAP/IAN pins of the 71M6541 • IB = current applied to the shunt S2 that is connected via the Remote Interface IC • CVD = error contribution from the voltage-divider • C4X = error contribution from the voltage reference of the 71M6541 • CS1 = error from the shunt resistor that is connected to the IAP/IAN pins of the 71M6541 • CS2 = error from the shunt resistor that is connected via the Remote Interface IC • C6X = error contribution from the voltage reference of the Remote Interface IC The equation can be simplified as follows: 2  VA ⋅ CVD ⋅ C4 X ⋅ IB ⋅ C S 2 ⋅ C6 X )  VA ⋅ CVD ⋅ IA ⋅ C S 1 ⋅ C4 X P= −  2 2    Or: P = VA CVD ⋅ C4 X {IA ⋅ CS1 ⋅ C4 X − IB ⋅ CS 2 ⋅ C6 X } 2 2.4.2 SOFTWARE FEATURES FOR TEMPERATURE COMPENSATION In the default settings for the Demo Code, the CECONFIG register has its EXT_TEMP bit (bit 22) set, which means that temperature compensation is performed by the MPU by controlling the GAIN_ADJA and GAIN_ADJB registers. In this context, GAIN_ADJA controls both current and voltage readings for phase A (i.e., the VA and IAP/IAN pins) whereas GAIN_ADJB controls both current and voltage readings for phase B (i.e., the VA and the 71M6X0X Remote Sensor Interface IC). In general, the GAIN_ADJA and GAIN_ADJB registers offer a way of controlling the magnitude of the voltage and current signals in the data flow of the CE code. A value of 16385 means that no adjustment is performed (unity gain), which means that the output of the gain adjust function is the same as the input. A value of 99% of 16385, or 16222, means that the signal is attenuated by 1%. The Demo Code bases its adjustment on the deviation from calibration (room) temperature DELTA_T and the coefficients PPMC and PPMC2 to implement the equation below: GAIN _ ADJ = 16385 + DELTA _ T ⋅ PPMC DELTA _ T 2 ⋅ PPMC 2 + 214 2 23 It can be seen easily that the gain will remain at 16385 (0x4001), or unity gain, when DELTA_T is zero. For complete compensation, the error sources for each channel have to be combined and curve fit to generate the PPMC and PPMC2 coefficients, as we will see in the following section. The PPMC and PPMC2 coefficients are in the following MPU RAM locations: • • 47 Phase A (IAP/IAN pins): PPMCA -- 0x0B, PPMC2A – 0x0F Phase B (IBP/IBN pins): PPMCB -- 0x0C, PPMC2B – 0x10 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 2.4.3 CALCULATING PARAMETERS FOR COMPENSATION 2.4.3.1 Shunt Resistors The TC of the shunt resistors can be characterized using a temperature chamber, a calibrated current, and a voltmeter with filtering capabilities. A few shunt resistors should be measured and their TC should be compared. This type of information can also be obtained from the manufacturer. For sufficient compensation, the TC of the shunt resistors must be repeatable. If the shunts are the only temperature-dependent components in a meter, and the accuracy is required to be within 0.5% over the industrial temperature range, the repeatability must be better than: R = (5000 PPM/°C) / (60°C) = 83.3 PPM/°C This means that for a shunt resistor with +200 PPM/°C, the individual samples must be within +116.7 PPM/°C and 283.3 PPM/°C. Let us assume a shunt resistor of 55 µΩ. This resistor is 10% above the nominal value of 50 µΩ, but this is of minor importance, since this deviation will be compensated by calibration. In a temperature chamber, this resistor generates a voltage drop of 5.4559 mV at -40°C and 5.541 mV at +85°C with 100 A applied. This is equivalent to a resistance deviation of 0.851 µΩ, or 15,473 PPM. With a temperature difference between hottest and coldest measurement of 125°C, this results in +124 PPM/°C. At high temperatures, this resistor will read the current 60°C * 124 PPM/°C, or 0.744% too high. This means that the GAIN_ADJA and GAIN_ADJB registers have to be adjusted by -0.744% at the same temperature to compensate for the TC of the shunt resistor. Let us assume that only linear components appear in the formula below, i.e., PPMC2 is zero. GAIN _ ADJ = 16385 + DELTA _ T ⋅ PPMC DELTA _ T 2 ⋅ PPMC 2 + 214 2 23 We must now find the PPMC value that decreases GAIN_ADJ by 0.744% when DELTA_T is +600 (DELTA_T is measured in tens of °C). We find PPMCS to be: PPMCS = 214 * (16263 – 16385) / 600 = -3331 2.4.3.2 Remote Sensor Reference Voltage Above the contribution of the TC from the shunt resistor, we will have to take into account the linear and quadratic deviation of the reference voltage of the Remote Sensor Interface IC. As mentioned above, we have to read the TRIMT register of the Remote Sensor Interface IC. This can be done with the CLI command >6R1.10. Let us assume, the command >6R1.10 returns the value 9082 which we can interpret as the binary sequence 1001 – 0000 – 1000 – 0010. The value of TRIMT is contained in the bits 1 through 8, i.e., 0100 – 0001, or 65 decimal. We can now calculate the TCs of the reference voltage (VREF) for the Remote Sensor Interface IC: TC1 = 3.50*10-4 - 6.04*10-6 * TRIMT = 3.50*10-4 - 6.04*10-6 * 65 = -42.6 * 10-5 -7 -9 -7 -9 -7 TC2 = -8.11*10 + 4.19*10 * TRIMT = -8.11*10 + 4.19*10 * 65 = - 5.39 * 10 These coefficients are in V/°C, somewhat different from the µV/°C given in other data sheets. Using these coefficients, we obtain 1.19557 V at -40°C and 1.19018 V at +85°C, assuming VREF was trimmed to 1.195 V at room temperature. If we had to compensate only for VREF, GAIN_ADJ would have to follow the curve of VREF that is shown in Figure 2-10. 48 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual GAIN_ADJ 16410 16400 GAIN_A… 16390 16380 16370 16360 16350 16340 16330 16320 16310 -40 -20 0 20 40 60 80 Figure 2-10: GAIN_ADJ over Temperature Some curve-fitting is required to find PPMC6X and PPMC26X coefficients that will generate the desired behavior of the GAIN_ADJ register. For this case, PPMC6X = -960 and PPMC26X = -610 approach the curve very accurately. The maximum deviation between GAIN_ADJ and the GAIN_ADJ’ synthesized by PPMC and PPMC2 coefficients is 0.00435%. Figure 2-11 shows how both functions almost overlap. 16410 16400 16390 16380 16370 16360 GAIN_ADJ 16350 GAIN_ADJ' 16340 16330 16320 16310 -40 -20 0 20 40 60 80 Figure 2-11: GAIN_ADJ and GAIN_ADJ’ over Temperature 49 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 2.4.3.3 Reference Voltage of the 71M6541 At a later time, it will be shown how the compensation coefficients for the reference voltage of the 71M6541 can be derived. For the moment, let us assume that we know these coefficients, and that they are PPMC4X = -820 and PPMC24X = -680. 2.4.3.4 Voltage-Divider In most cases, especially when identical resistor types are used for all resistors of the voltage-divider ladder, the TC of the voltage-divider will be of minor influence on the TC of the meter. If desired, the voltage-divider can be characterized similar to the shunt resistor as shown above. Let us assume, applying 240 Vrms to a meter and recording the RMS voltage displayed by the meter at -40°C, room temperature, +55°C, and at +85°C, we obtain the values in the center column of Table 2-2. Table 2-2: Temperature-Related Error Sources Temperature [°C] Displayed Voltage Normalized Voltage -40 246.48 240.458 25 246.01 240.0 55 245.78 239.78 85 245.56 239.57 After normalizing with the factor 240/246.01 to accommodate for the initial error, we obtain the values in the third column. We determine the voltage deviation between highest and lowest temperature to be -0.88 V, which is equivalent to -3671 PPM, or -29.4 PPM/°C. Finally, we obtain a PPMCVD value of 788. 2.4.3.5 Combining the Coefficients for Temperature Compensation The TC formula for equation 2 is restated below: 2  VA ⋅ CVD ⋅ C4 X ⋅ IB ⋅ C S 2 ⋅ C6 X )  VA ⋅ CVD ⋅ IA ⋅ C S 1 ⋅ C4 X P= −  2 2    After characterizing all major contributors to the TC of the meter, we have all components at hand to design the overall compensation. For simplification purposes, we have decided to ignore CVD. For the control of GAIN_ADJA, we will need the following coefficients: CS1: The PPMCS = -3331 determined for the shunt resistor. PPMC2S for the shunt resistor is 0. CVD: The PPMCVD value of 788 determined for the voltage-divider. C4X: PPMC4X = -820 and PPMC24X = -680 We will find that coefficients can simply be added to combine the effects from several sources of temperature dependence. Before we do that, we must consider that the equations for temperature compensation are structured in a special way, i.e.,: • If an error source affects both current and voltage measurements, the original PPMC and PPMC2 coefficients are used. • If an error source affects only one measurement, the original PPMC and PPMC2 coefficients are divided by 2. Following this procedure, we obtain the coefficients for GAIN_ADJA as follows: 50 • PPMCA = PPMCS/2 + PPMC4X + PPMCVD/2 = -3331/2 - 820 + 788/2 = -2092 • PPMC2A = PPMC2S + PPMC24X = -680 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual For the control of GAIN_ADJB, we will need the following coefficients: CS2: Since we assume that the shunt resistors are very similar with respect to their TC, we use the value found for the shunt connected at phase B (PPMCS = -3331). Again, PPMC2S for the shunt resistor is 0. Since this coefficient applies to the current measurement only, we will have to apply the ½ factor mentioned above. C4X: PPMC4X = -820 and PPMC24X = -680, as already stated above. Since these coefficients apply to the voltage measurement only, we will have to apply the ½ factor mentioned above. C6X: PPMC6X = -960 and PPMC26X = -610. Since these coefficients apply to the current measurement only, we will have to apply the factor of ½ that was mentioned above. CVD: The PPMCVD value of 788 determined for the voltage-divider. We obtain the coefficients for GAIN_ADJB as follows: • PPMCB = PPMCS/2 + PPMC4X/2 + PPMC6X/2 + PPMCVD/2 = -3331/2 - 820/2 - 960/2 + 788/2 = -2162 • PPMC2B = PPMC22S/2 + PPMC24X/2 + PPMC6X/2 = 0 - 680/2 -610/2 = -985 2.5 TESTING THE DEMO BOARD This section will explain how the 71M6541F IC and the peripherals can be tested. Hints given in this section will help evaluating the features of the Demo Board and understanding the IC and its peripherals. Demo Board. It interfaces to a PC through a 9 pin serial port connector. It is recommended to set up the demo board with no live AC voltage connected, and to connect live AC voltages only after the user is familiar with the demo system. BEFORE CONNECTING THE DEMO BOARD TO A CALIBRATION SYSTEM OR OTHER HIGH-VOLTAGE SOURCE IT IS RECOMMENDED TO MEASURE THE RESISTANCE BETWEEN THE LINE AND THE NEUTRAL TERMINALS OF THE DEMO BOARD WITH A MULTIMETER. ANY RESISTANCE BELOW THE 1 MΩ RANGE INDICATES A AFAULTY CONNECTION RESULTING INDESTRUCTION OF THE 71M6541. 2.5.1 FUNCTIONAL METER TEST This is the test that every Demo Board has to pass before being integrated into a Demo Kit. Before going into the functional meter test, the Demo Board has already passed a series of bench-top tests, but the functional meter test is the first test that applies realistic high voltages (and current signals from current transformers) to the Demo Board. Figure 2-12 shows a meter connected to a typical calibration system. The calibrator supplies calibrated voltage and current signals to the meter. It should be noted that the current flows through the shunts or CTs that are not part of the Demo Board. The Demo Board rather receives the voltage output signals from the current sensor. An optical pickup senses the pulses emitted by the meter and reports them to the calibrator. Some calibration systems have electrical pickups. The calibrator measures the time between the pulses and compares it to the expected time, based on the meter Kh and the applied power. 51 Rev 4.0 Meter under Test AC Voltage Optical Pickup for Pulses Current CT Pulse Counter Calibrated Outputs 71M6541 Demo Board REV 3.0 User’s Manual PC Calibrator Figure 2-12: Meter with Calibration System Figure 2-13 shows the screen on the controlling PC for a typical Demo Board. The error numbers are given in percent. This means that for the measured Demo Board, the sum of all errors resulting from tolerances of PCB components, current sensors, and 71M6541F tolerances was –3.41%, a range that can easily be compensated by calibration. Figure 2-14 shows a load-line obtained with a 71M6541 in differential mode. As can be seen, dynamic ranges of 2,000:1 for current can be achieved with good circuit design, layout, cabling, and, of course, good current sensors. Figure 2-13: Calibration System Screen 52 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual Form 2S - Wh Error [%] at 0°, 60° and 300° Phase Angle, 240 V/60 Hz 0.25 0.20 0.15 0.10 0.05 0.00 60° 300° 0° -0.05 -0.10 -0.15 -0.20 -0.25 0.1 1 10 100 1000 Figure 2-14: Wh Load Lines at Room Temperature with 71M6201 and 50 µΩ Shunts 2.6 SENSORS AND SENSOR PLACEMENT Both sensor self-heating and sensor placement has to be considered in order to avoid side effects that can affect measurement accuracy. These considerations apply in general to both ANSI meters and IEC meters. Both meter variations will be discussed below. 2.6.1 SELF-HEATING The effect of self-heating will be most pronounced at maximum current and depends on the following parameters: • Nominal shunt resistance • Current through the shunt resistor • Thermal mass • Heat conduction away from the shunt (thermal resistance towards the environment) • Temperature coefficient of copper and resistive material. It is quite obvious that the nominal resistance of the shunt resistor should be kept as low as possible. Table 1-9 shows a few combinations of shunt resistance and 71M6X0X part number. The parts with part numbers corresponding to higher current capacity are designed to work with low shunt resistance. Lowering the shunt resistance below the recommended limits decreases accuracy and repeatability. Good heat conduction can help to maintain the shunt temperature. Attaching the shunt to solid metallic structures such as meter terminal blocks helps decreasing the thermal resistance. This, of course, applies to meters where the terminals and other mechanical parts can be considered heat sinks, i.e., they do not heat up due to other effects. The thermal mass will control how long it takes the sensor to reach its maximum temperature. Meters, for which only short-time maximum currents are applied, can benefit from a large thermal mass, since it will increase the time constant of the temperature rise. The temperature coefficient (TC) of the shunt is a very important factor for the self-heating effect. Shunts with a TC of just a few PPM/°C can maintain good shunt accuracy even in the presence of significant self-heating. There are several methods that can be applied in the meter code that can minimize the effects of self-heating. 53 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual The effect of shunt self-heating can be described by the following formulae. First, the relative output of a shunt resistor is: ΔV/V = ΔR/R ΔR is a function of the change in temperature, the temperature coefficient, the thermal resistance, and, of course, the applied power, which is proportional to the square of the current: ∆V ∆R R ⋅ ∆T ⋅ TC R = = = I 2 R ⋅ RTH ⋅ TC R V R R Ultimately, it is up to the meter designer to select the best combination of shunt resistance, TC, shunt geometry and potential software algorithms for the given application. 2.6.2 PLACEMENT OF SENSORS (ANSI) The arrangement of the current terminals in an ANSI meter enclosure predetermines shunt orientation, but it also allows for ample space in between the sensors, which helps to minimize cross-talk between phases. A good practice is to shape the shunts like blades and to place them upright so their surfaces are parallel. In a 16S meter, the distance between the phase A sensor and the phase B sensor is roughly 1”, which makes these two phases most critical for cross-talk. For the form 2S meter, which is a very frequently used single-phase configuration, the distance between the sensors is in the range of 2.75”, which makes this configuration much less critical. However, even for this case, good sensor placement is essential to avoid cross-talk. Sensor wires should be tightly twisted to avoid loops that can be penetrated by the magnetic fields of the sensors or conductors. 54 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 2.6.3 PLACEMENT OF SENSORS (IEC) The arrangement of the current terminals in a typical IEC meter enclosure predetermines the spacing of the shunts, and usually allows for only for 20 to 22 mm center-to-center spacing between the shunts. This means that the clearance between adjacent shunts is typically only 10 mm or less. A typical arrangement is shown in Figure 2-15, left side. This arrangement is not optimized for suppression of cross-talk. In order to minimize cross-talk between phases, the shunts should be turned by 90 degrees as shown in Figure 2-15, right side. In this arrangement, the sensitive areas of the shunts are kept away from the adjacent currents. Figure 2-15: Typical Sensor Arrangement (left), Recommended Arrangement (right) Other arrangements are shown in Figure 2-16. In the left figure, the shunts are shown swiveled by 90 degrees towards the terminals. In the right figure, the shunts are shown staggered in height, for example by using spacers. It is useful to minimize the loop area formed by the Manganin zone of the shunts and the wires. As with the ANSI sensors, it is recommended that sensor wires are tightly twisted to avoid loops that can be penetrated by the magnetic fields of the sensors or conductors. Figure 2-16: Improved Sensor Arrangement 55 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 2.6.4 OTHER TECHNIQUES FOR AVOIDING MAGNETIC CROSSTALK With very high currents or close distances between shunt sensors, magnetic pickup or cross-talk will sometimes occur even if good placement practices are followed. One mechanism for cross-talk is shown in Figure 2-17, where the Manganin zone and the sensor wire act as a loop that will generate an output voltage similar to that generated by a Rogowski coil. The effect of this loop can be compensated by adding a second loop on the opposite side of the shunt resistors, as shown in Figure 2-18. Optional contact for voltage Sensor wires Copper Loop Manganin Figure 2-17: Loop Formed by Shunt and Sensor Wire Symmetrical loops Figure 2-18: Shunt with Compensation Loop Since the compensation loop is impractical, a similar compensation effect can be achieved by attaching the sensor wires in the center, as shown in Figure 2-19. An economical approach to this technique is to drill holes in 1 the center of the shunt resistor for attachment of the sensor wires . Figure 2-19: Shunt with Center Drill Holes 1 Patent pending 56 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 57 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 3 3 HARDWARE DESCRIPTION 3.1 71M6541-DB DESCRIPTION: JUMPERS, SWITCHES AND TEST POINTS The items described in the following tables refer to the flags in Figure 3-1. 58 Item # Reference Designator Name Use 1 TP2 GND GND test point. 2 JP58 WPULSE 3 D5 Wh 4 D6 VARh 2-pin header connected to the Wh pulse LED Wh pulse LED. VARh pulse LED. Selector for the operation of the IC when main power is removed. A jumper across pins 2-3 (default) indicates that no external battery is available. The IC will stay in brownout mode when the system power is down and it will communicate at 9600bd. A jumper across pins 1-2 indicates that an external battery is available. The IC will be able to transition from brownout mode to sleep and LCD modes when the system power is down and it will communicate at 300bd. 5 JP1 BAT MODE 6 JP44 XPULSE 3-pin header that connects XPULSE pin to the LCD. The XPULSE pin should be configured as an LCD pin when a jumper is placed in the 1-2 position. 7 JP45 YPULSE 3-pin header that connects YPULSE pin to the LCD. The YPULSE pin should be configured as an LCD pin when a jumper is placed in the 1-2 position. 2-pin header that connects the V3P3D pin to parts on the board that use the V3P3D net for their power supply. For supply current measurements in brownout mode, the jumper on JP53 may be removed. 8 JP53 V3P3D 9 U5 -- 10 TP1 TMUXOUT, TMUX2OUT 11 BT1 -- Location of optional battery for the support of battery modes. (Located on the bottom) 12 BT2 -- Location of optional battery for the support of RTC and non-volatile RAM. BT2 has an alternate circular footprint at location BT3. The IC 71M6541 soldered to the PCB. Test points for access to the TMUXOUT and TMU2XOUT pins on the 71M6541. Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual Item # Reference Designator Name 13 J21 DEBUG Connector for Debug Board. 2x8 pin male header. 14 SW5 RESET Chip reset switch: When the switch is pressed, the RESET pin of the IC is pulled high which resets the IC into a known state. 15 J12 -- 2-pin header. If a jumper installed, the battery BT1 will be connected to the V3P3SYS net. 16 J13 -- 2-pin pin header. If a jumper installed, the battery BT2/BT3 will be connected to the V3P3SYS net. 17 BT3 -- Alternate footprint for BT2. A circular battery may be mounted in this location (on the bottom of the board). Use 18 SW3 PB Pushbutton connected to the PB pin on the IC. This pushbutton can be used in conjunction with the Demo Code to wake the IC from sleep mode or LCD mode to brown-out mode. 19 JP20 5.0 VDC Circular connector for supplying the board with DC power. Do not exceed 5.0 VDC at this connector! 20 J7 IAP/IAN 2-pin header connected to pins IAP and IAN on the IC. 21 J6 VA IAN_IN, IAP_IN 22 J3 2-pin header connected to pins VA and V3P3A on the IC 2-pin header for the connection of the primary (nonisolated) shunt. This header is on the bottom of the board. Since the board is at line voltage, the shunt corresponding to the line side of the meter should be connected here. Caution: Connecting the shunt corresponding to the neutral voltage will result in board damage! 23 A jumper is placed across JP6 to activate the internal AC power supply. JP6 Caution: High Voltage! Do not touch! 24 J11 NEUTRAL LINE 25 J4 The NEUTRAL voltage input connected to V3P3. This input is a spade terminal mounted on the bottom of the board. LINE is the line voltage input to the board. It has a resistor divider that leads to the pin on the IC associated with the voltage input to the ADC. This input is a spade terminal mounted on the bottom of the board. Caution: High Voltage! Do not touch this pin! 26 27 59 J10 J8 IBP, IBN 2-pin header connected to pins IBP and IBN on the IC -- 2-pin header on the bottom of the board for optional connection of a CT. When using a CT, the burden resistor locations R33/R34 have to be populated. Also, the resistors and capacitors for filtering (R26/C25, R57/C12) and for biasing the IBP/IBN inputs (R86, R87) must be populated. IBP_IN, IBN_IN 2-pin header for the connection of the secondary (remote) shunt. This header is on the bottom of the board. The shunt connected here should be the one corresponding to the neutral side of the meter. 28 J5 29 JP2 30 JP3 ICE_E 31 JP7 SEGDIO51 5-pin header for access to OPT_TX and OPT_RX signals. 3-pin header for the control of the ICE_E signal. A jumper across pins 1-2 disables the ICE interface; a jumper across pins 2-3 enables it. 2-pin header that allows connecting the Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual Item # Reference Designator Name Use SEGDIO51/OPT_TX pin to the LCD. If the second UART is used, the jumper should be removed from the header. 32 J14 EMULATOR I/F 2x10 emulator connector port for the Signum ICE ADM-51 or for the TFP2 Flash Programmer. 33 JP54 E_RXTX Three 2-pin headers that connects the E_RXTX, E_RXTX, and E_TCLK pins to the LCD. The emulator pins should be configured as LCD pins when this jumper is inserted. 34 JP8 SEGDIO55 2-pin header that allows connecting the SEGDIO51/OPT_RX pin to the LCD. If the second UART is used, the jumper should be removed from the header. 35 J19 SPI 36 JP9, JP10, JP11, JP12 SPI_DO, SPI_DI, SPI_CK, SPI_CSZ Four 2-pin headers that connect the SPI_DI, SPI_DO, SPI_CK, and SPI_CSZ pins to the LCD. The SPI pins should be configured as LCD pins when these jumpers are inserted 37 CN1 USB PORT This connector is an isolated USB port for serial communication with the 71M6541. 38 U8 LCD 39 JP59 VPULSE 40 JP5 UART_RX, ROUT 2X5 header providing access to the SPI slave interface. 3-row LCD with 6 7-segment digits per row and special metering symbols. 2-pin header connected to the VARh pulse LED 2-pin header for connection of the RX output of the isolated USB port to the RX pin of the 71M6541. When the Demo Board is communicating via the USB port, a jumper should be installed on JP5. When the Demo Board is communicating via the Debug Board plugged into J21, the jumper should be removed. Table 3-1: 71M6541-DB REV 3.0 Description 60 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual Figure 3-1: 71M6541-DB REV 3.0 - Board Description (Default jumper settings are indicated in yellow) 61 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 3.2 BOARD HARDWARE SPECIFICATIONS PCB Dimensions Width, length Thickness Height w/ components 134 mm x 131 mm (5.276” x 5.157”) 1.6mm (0.062”) 40 mm (1.57”) Environmental Operating Temperature Storage Temperature Power Supply Using internal AC supply DC Input Voltage (powered from DC supply) Supply Current Input Signal Range AC Voltage Signal(VA) AC Current Signals (IA) from Shunt/CT -40°…+85°C -40°C…+100°C 100 V…240 V RMS 5.0 VDC ±0.3 V < 10 mA typical 0…240 V RMS 0…27.8 mV peak for Remote Sensor Input 0…31.5 mV peak for direct input (IAP/IAN) Interface Connectors DC Supply (J20) Emulator (J14) Voltage Input Signals Current Input Signals USB port (PC Interface) Optional Debug Board (J2) SPI Interface 2.5 mm circular (Switchcraft RAPC712X) 10x2 header, 0.05” pitch Spade terminals on PCB bottom 0.1” 1X2 headers on PCB bottom USB connector 8x2 header, 0.1” pitch 5x2 header, 0.1” pitch Functional Specification Program Memory NV memory Time Base Frequency 64 KB FLASH memory 1Mbit serial EEPROM 32.768kHz, ±20PPM at 25°C Controls and Displays RESET PB Numeric Display “Wh” “VARh” Push-button (SW5) Push-button (SW3) 3X8-digit LCD, 7 segments per digit, plus meter symbols red LED (D5) red LED (D6) Measurement Range Voltage Current 62 120…600 V rms (resistor division ratio 1:3,398) Dependent on shunt resistance or CT ratio/burden resistor Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 63 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 4 4 APPENDIX This appendix includes the following documentation, tables, and drawings: 71M6541 Demo Board Description D6541 REV 3.0 Demo Board Electrical Schematic D6541 REV 3.0 Demo Board Bill of Materials D6541 REV 3.0 Demo Board PCB layers (copper, silkscreen, top and bottom side) 71M6541 IC Description 71M6541 Pin Description 71M6541 Pinout 64 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 4.1 71M6541-DB ELECTRICAL SCHEMATIC Positive Supply COMBO FOOTPRINT 100uF/15V D3 1N4148WS 0.22uF C8 D15 Power Down Circuit Note: C29, C32, and C34 have been reversed on the silk screen. This schematic is correct! 1 2 3 Q2 BC857 R18 275V 5VDC C32 NEUTRAL_IN JP20 R7 2M 1N4148WS 30K D2 BOARD_SUPPLY SEGDIO8 D7 1N4148WS D13 1N4148WS D14 1N4148WS R20 8.06K U1 C29 1000uF/6V R13 2 1 C13 D10 1N4148WS D11 100uF/15V 1N4148WS 1. Under Normal Conditions, SEGDIO8 is high and indicates presence of power 2. Under NEUTRAL Cut Conditions, SEGDIO8 is low and current is greater than 1 Amp 3. Under Power Down Conditions (VA_IN down), SEGDIO8 is low and current is zero R19 100uF/15V Negative Supply 2 D4 1N4148WS Shunt Regulator 150 Negative Supply 1 V3P3SY S L11 Ferrite Bead 600ohm Off-Page Connectors C58 100pF 2 R141 D9 UCLAMP3301D R66 R64 R47 R39 V3P3SY S Ferrite Bead 600ohm VA 1 NEUTRAL_IN 100 R21 25.2K C26 1 2 1 LINE Q4 BCX70 6.04K 20K Negative Supply 3 JP6 C4 0.1uF C34 33uF/6.3V R14 Q3 BCX70 LINE R6 8.20K 0805 TL431 R27 130 S1J-E3 2M 270K 0805 270K 0805 4.7K 0805 L13 R32 750 805 VA 2 1 C9 1000pF 2 RV1 VARISTOR J6 SEGDIO8 2 1 V3P3A LINE J4 1 + Ferrite Bead 600ohm 1 L14 Ferrite Bead 600ohm C40 470uF V3P3A C56 0.1uF L8 C16 1000pF R23 750 Ferrite Bead 180ohm IAP IAP J3 IAP_IN 1 2 IAN_IN 1 2 IAP_IN IAN_IN L2 R84 10K R24 3.4 1206 DNP IA_IN R25 3.4 1206 DNP IAN C24 1000pF J7 C67 0.1uF TESTPOINTTP3 J5 INP_IN 1 2 Ferrite Bead 600ohm R22 1K 0 C17 1 2 L4 INN_IN IN_IN 1000pF C23 Ferrite Bead 600ohm L5 R55 0 1000pF U15 1 1 DNP LOAD 2 1 IBN 2 1 IBP IAN Shunt Connection R88 C15 100pF IA C10 1000pF L3 Ferrite Bead 180ohm C14 1000pF V3P3A R85 10K R26 0 R56 750 750-11-0056 IBN 5 INP 6 INN 7 8 TMUX GND INP SN INN SP TEST VCC 71M6601 4 3 SN 2 SP L6 Ferrite Bead 600ohm T1 1 4 2 1 1 2 3 2 1 R34 3.4 1206 R33 3.4 1206 For Optional CT Def ault C35 1000pF DNP J10 V3P3A Ferrite Bead 600ohm L7 C11 0.47uF C25 1000pF DNP R86 10K DNP J8 Def ault 2 1 C68 0.1uF R87 10K DNP 0 R57 C12 1000pF DNP C37 1000pF DNP 2 1 IB IBP GND_R6000 R89 Title 71M6541 Demo Board REV 3.0 J11 1 1 NEUTRAL Ferrite Bead 600ohm NEUTRAL_IN 1K Isolated Sensor and signal transform er Size B Document Number D6541 Rev 3.0 L12 Date: Tuesday , May 10, 2011 Sheet 1 of 2 Figure 4-1: 71M6541-DB REV 3.0 Demo Board: Electrical Schematic 1/2 65 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual V3P3D SEGDIO8 J13 2 1 PB 1K C18 0.1uF R103 10K 2 2 4 6 8 10 HDR5X2 JP8 HDR2X1 R4 SW5 RESET 100 C21 0.1uF R106 1K 1 V3P3D 2 1 * HDR2X1 C28 0.1uF C50 1000pF C62 0.1uF * LED D8 R8 2 U3 1 RX_USB 2 3 GND_USB 4 5 6 7 8 TMUX2OUT TMUXOUT Off-Page Connectors R9 R10 R11 62 62 62 C55 100pF IAP U2 0.1uF VCCIO RXD RI# GND NC DSR# DCD# CTS# FT232RQ AGND NC CBUS0 CBUS1 GND VCC RESET# GND V3P3SY S IAN IBP IBN 1 2 3 4 RX_USB TX_USB GND_USB VDD1VDD2 VOA VIA VIB VOB GND1GND2 8 7 6 5 V3P3SY S UART_TX UART_RX_ISO C27 0.1uF ADUM3201 TXRXLED 24 23 22 21 20 19 18 17 CN1 L1 VBUS USB-B DD+ GND +5V_USB +5V -D_USB +D_USB 1 2 3 4 +5V_USB Ferrite Bead 600ohm C5 C3 0.01uF C6 0.1uF GND_USB USB Interface Title 71M6541 Demo Board REV 3.0 C33 Size B 0.1uF Date: Document Number D6541 Monday , May 09, 2011 Rev 3.0 Sheet 2 of Figure 4-2: 71M6541-DB REV 3.0 Demo Board: Electrical Schematic 2/2 66 4.7uF R2 0 SEGDIO8 V3P3A COM0 COM1 COM2 SEGDIO7 * SEGDIO4 SEGDIO22 * SEGDIO5 SEGDIO9 SEGDIO10 SEGDIO11 SEGDIO12 SEGDIO13 SEGDIO14 SEGDIO19 SEGDIO20 SEGDIO21 SEGDIO24 SEGDIO25 SEGDIO44 SEGDIO45 SEGDIO36 * SEGDIO37 * SEGDIO48 * SEGDIO38 * SEGDIO39 * SEGDIO49 * SEGDIO55 * SEGDIO50 * +5V_USB C7 UART_RX_ISO VA 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 COM0 COM1 COM2 1D,1G,1A DP1,1C,1B DP2,2E,2F 2D,2G,2A DP0,2C,2B X4,3E,3F 3D,3G,3A DP3,3C,3B X3,4E,4F 4D,4G,4A DP4,4C,4B X2,5E,5F 5D,5G,5A DP5,5C,5B X1,6E,6F 6D,6G,6A DP6,6C,6B 10D,10G,10A DP10,10C,10B X13,11E,11F,X10,X17,X18 11D,11G,11A DP11,11C,11B X14,12E,12F,X12,X21 12D,12G,12A DP12,12C,12B,X11,X20,X19 * Note: These pins must be assigned as indicated, all other pins can be swapped for layout purposes, but PCB linkages must remain intact. JP2 1 2 3 4 5 V3P3D UART_RX UART_TX * 7 & PIN 33 PIN * 10 & PIN 53 PIN PIN 13 & PIN 50 PIN 16 & PIN 47 PIN 19 & PIN 44 PIN 22 & PIN 41 PIN 25 & PIN 38 1K +5V_USB HDR2X1 2 4 6 8 10 12 14 16 Debug Connector 2 JP53 V3P3D_BRN V2P5 ICE_E E_RXTX E_TCLK E_RST UART_RX UART_TX OPT_TX * 1000pF HDR8X2 Pull jumper JP53 for BRN current measurements. * * * * * * * V3P3SY S JP5 C97 J21 15pF R12 100K SEGDIO39 1 3 5 7 9 11 13 15 XIN VBAT_RTC VBAT V3P3SY S IBP IBN C1 GND_USB JP7 HDR2X1 V3P3SY S SEGDIO511 OPT_TX 2 V3P3SY S OPT_RX SEGDIO551 2 JP12 HDR2X1 SEGDIO36 1 SEGDIO39/SPI_CKI SEGDIO44 SEGDIO45 SEG46/TMUX2OUT SEG47/TMUXOUT RESET PB VLCD VREF IAP IAN V3P3A VA TEST GNDA XOUT J19 JP11 HDR2X1 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 SPI Interface 1 3 5 7 9 1 VBAT SW3 C47 10uF LCD VLS-6648 COM3 COM4 COM5 X5,1E,1F,7F,13F,13E FE,13G,13D 7D,13A,13C 7C,13B,DP13 7G,14F,14E 7B,14G,14D 7A,14A,14C DP7,14B,DP14 8F,15F,15E 8E,15G,15D 8D,15A,15C 8C,15B,DP15 8G,16F,16E 8B,16G,16D 8A,16A,16C DP8,16B,DP16 9F,17F,17E 9E,17G,17D 9D,17A,17C 9G,17B,DP17 9C,18F,18E 9A,18G,18D X7,X8,X6,9B,18A,18C DP9,18B,DP18 X15,10E,10F,X9,X16,X22 6 5 R105 10K V3P3D R1 2 2 R3 0 R104 10K SDCK SDATA SPI_DI SPI_DO SPI_CK SPI_CSZ V3P3D U8 COM3 1 COM4 2 COM5 3 SEGDIO6 4 SEGDIO365 SEGDIO376 SEGDIO387 SEGDIO398 SEGDIO559 SEGDIO710 SEGDIO411 SEGDIO22 12 SEGDIO513 SEGDIO914 SEGDIO10 15 SEGDIO11 16 SEGDIO12 17 SEGDIO13 18 SEGDIO14 19 SEGDIO19 20 SEGDIO20 21 SEGDIO21 22 SEGDIO24 23 SEGDIO25 24 SEGDIO44 25 SEGDIO23 26 SEGDIO45 27 SEGDIO51 28 6 5 SER EEPROM SER EEPROM JP10 HDR2X1 JP9 HDR2X1 V3P3D 8 7 6 5 1 VCC WP SCL SDA 1 A0 A1 A2 GND Note: Remove JP60-JP63 before using SPI header SEGDIO37 2 1 2 3 4 C20 0.1uF 1 U4 C51 0.1uF 10pF 32.768KHz XIN VBAT_RTC VBAT V3P3SY S IBP IBN GNDD V3P3D VDD ICE_E SEG48/E_RXTX SEG49/E_TCLK SEG50/E_RST RX TX SEGDIO51/OPT_TX 71M6541 C2 Y1 33 SEGDIO38 SERIAL EEPROM SPI_DI/SEGDIO38 SPI_DO/SEGDIO37 SPI_CSZ/SEGDIO36 COM0 COM1 COM2 COM3 SEGDIO27/COM4 SEGDIO26/COM5 SEGDIO25 SEGDIO24 SEGDIO23 SEGDIO22 SEGDIO21 SEGDIO20 SEGDIO19 L16 Ferrite Bead 600ohm Note: Place C1, C2, Y1 close to U5 32 31 30 29 28 27 26 25 R142 1K 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 HDR2X1 RTS# DTR# TXD NC OSCO OSCI TEST NC J14 C49 1000pF JP3 PCB Linkage(LCD): * & PIN 36 PIN 6 & PIN 35 * 9 & PIN 30 & PIN 32 PIN PIN 11 & PIN 52 *PIN 12 & PIN 51 PIN 14 & PIN 49 PIN 15 & PIN 48 PIN 17 & PIN 46 PIN 18 & PIN 45 PIN 20 & PIN 43 PIN 21 & PIN 42 PIN 23 & PIN 40 PIN 24 & PIN 39 PIN 27 & PIN 37 * PIN 5 SLUG ICE_E C52 1000pF * PIN 8 CBUS4 CBUS2 CBUS3 NC NC USBDP USBDM 3V3OUT 1 2 3 C22 0.1uF VPULSE 9 10 11 12 13 +D_USB 14 -D_USB 15 16 22pF 62 62 62 1000pF SEGDIO14 SEGDIO13 SEGDIO12 SEGDIO11 SEGDIO10 SEGDIO9 SEGDIO8/DI SEGDIO7/YPULSE SEGDIO6/XPULSE SEGDIO5 SEGDIO4 SEGDIO3/SDATA SEGDIO2/SDCK SEGDIO1/VPULSE SEGDIO0/WPULSE SEGDIO55/OPT_RX 22pF R15 R16 R17 SPI_DI SPI_DO SPI_CSZ COM0 COM1 COM2 COM3 COM4 COM5 SEGDIO25 SEGDIO24 SEGDIO23 SEGDIO22 SEGDIO21 SEGDIO20 SEGDIO19 19 17 15 13 11 9 7 5 3 1 C63 0.1uF SEGDIO14 SEGDIO13 SEGDIO12 SEGDIO11 SEGDIO10 SEGDIO9 SEGDIO8 YPULSE XPULSE SEGDIO5 SEGDIO4 SDATA SDCK VPULSE WPULSE OPT_RX C30 + C45 10uF C36 1000pF 2 XOUT DNP U5 20 18 16 14 12 10 8 6 4 2 C64 SPI_CK SEGDIO44 SEGDIO45 TMUX2OUT TMUXOUT RESET PB VLCD VREF IAP IAN V3P3A VA BT3 BATTERY 1 1 1 C31 V3P3A + R76 VARh 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 2 1 BT2 BATTERY DNP ICE Header C57 1000pF V3P3SY S 10K SSL-LX5093SRC/E JP59 1 2 HDR2X1 JP57 HDR2X1 E_RXTX E_TCLK E_RST WPULSE V3P3SY S Emulator I/F 1-2: disabled 2-3: enabled D6 1 2 1 2 2 2 1 + C61 1000pF C60 0.1uF V3P3D R74 2 10K SSL-LX5093SRC/E JP58 1 2 V3P3SY S TP1 SEGDIO50 SEGDIO49 JP55 HDR2X1 Wh HDR2X1 TMUXOUT TMUX2OUT JP45 JP44 SEGDIO48 1 V3P3SY S BT1 BATTERY DNP VBAT_RTC JP54 HDR2X1 D5 V3P3SY S V3P3A Note: Batteries not populated TP2 1 2 3 3 2 1 3 2 1 2 1 2 1 + C43 1000pF SEGDIO7 BAS21 J12 VBAT C19 0.1uF SEGDIO6 Y PULSE XPULSE A V3P3SY S C 100K DNP Remove jumper on JP1 when using power-downJP1 circuit. PULSE OUTPUTS Note: Remove Jumpers Before Using X/Y Pulse D1 R5 Rev 4.0 2 71M6541 Demo Board REV 3.0 User’s Manual 4.2 71M6541-DB BILL OF MATERIAL Table 4-1: 71M6541-DB REV 3.0: Bill of Material Item Q Reference Part Footprint Digi-Key P/N Mouser P/N Manufacturer Manufacturer P/N Tol Rating HDR DNP 1 2 BT1,BT2 BATTERY 2 1 BT3 BATTERY 3 4 5 6 7 1 1 1 3 15 USB-B 15pF 10pF 0.1uF 0.1uF 8 9 1 1 CN1 C1 C2 C3,C7,C27 C4,C18,C19,C20,C21,C22, C28,C33,C51,C56,C60,C62, C64,C67,C68 C5 C6 BAT 3 PIN BARREL COMBO BAT CR2032 MAX USBV 603 603 805 603 0.01uF 4.7uF 603 805 478-1383-1-ND 587-1782-1-ND 10 1 C8 0.22uF Block BC1609-ND Vishay BFC233820224 ±10% 275V 11 1000pF 603 445-1298-1-ND TDK C1608X7R2A102K ±10% 100V 12 13 14 15 16 17 16 C9,C10,C14,C16,C17,C23, C24,C36,C43,C49,C50,C52, C57,C61,C63,C97 1 C11 4 C12,C25,C35,C37 3 C13,C26,C32 3 C15,C55,C58 1 C29 2 C30,C31 0.47uF 1000pF 100uF/15V 100pF 1000uF/6V 22pF 603 603 CAP P833-ND 603 CAP P5115-ND 603 445-1314-1-ND 445-1298-1-ND P833-ND 445-1281-1-ND P5115-ND 445-1273-1-ND TDK TDK Panasonic TDK Panasonic TDK C1608X7R1H104K C1608X7R2A102K ECE-A1CKA101 C1608C0G1H101J ECA-0JM102 C1608C0G1H220J ±10% ±10% ±20% ±5% ±20% ±5% 50V 100V 16V 100V 6.3V 50V 18 1 C34 33uF/6.3V A 478-1666-1-ND SIZE_3216_CAP Panasonic TAJA336K006RNJ ±20% 6.3V 19 1 C40 470uF ECE-A1AKS101 20 21 22 23 2 1 1 8 10uF BAS21 S1J-E3 1N4148WS 24 25 26 2 1 1 C45,C47 D1 D2 D3,D4,D7,D10,D11,D13,D14, D15 D5,D6 D8 D9 27 4 JP1,JP3,JP44,JP45 28 1 JP2 29 23 TP1,J3,JP5,J5,JP6,J6,JP7, 30 31 1 2 J7,JP8,J8,JP9,JP10,J10, JP11,JP12,J12,J13,JP53, JP54,JP55,JP57,JP58,JP59 JP20 J4,J11 32 1 J14 33 1 J19 34 1 J21 35 11 L1,L4,L5,L6,L7,L8,L11, L12,L13,L14,L16 36 2 L2,L3 37 38 1 2 Q2 Q3,Q4 39 1 RV1 40 41 42 43 44 3 1 1 1 1 R1,R88,R89 R2 R3 R4 R5 67 CYL/D.400/LS. 200/.034 SM/CT_3216 SOT-23 AC SMA/DIODE DNP DNP 609-3657-ND 445-1237-1-ND 445-1269-1-ND 478-3351-1-ND 445-1314-1-ND FCI 806-KUSBVX-BS1N-W TDK C1005C0G1H150J TDK C1608C0G1H100D AVX Corporatio 08055C104MAT2A TDK C1608X7R1H104K AVX Corporatio 08055C103KAT2A Taiyo Yuden TMK212BJ475KG-T 594-2222-33820224 ±5% ±5% 50V 50V ±10% 50V P963-ND Panasonic 478-1672-1-ND BAS21FSCT-ND S1J-E3/61TGICT-ND 1N4148WSFSCT-ND AVX TAJB106K010R Fairchild BAS21 Vishay/Genera S1J-E3/61T Fairchild 1N4148WS SSL-LX5093SRC/E LED6513 LED 805 UCLAMP3301D SOD-323 BLKCON.100/V HDR3X1 H/TM1SQ/W.1 00/3 BLKCON.100/V HDR5X1 H/TM1SQ/W.1 00/5 BLKCON.100/V HDR2X1 H/TM1SQ/W.1 00/2 67-1612-ND L62415CT-ND UCLAMP3301DCT-ND Lumex CML Semtech SSL-LX5093SRC/E CMD17-21UGC/TR8 UCLAMP3301D.TCT S1011E-36-ND Sullins PBC36SAAN 0.1 S1011E-36-ND Sullins PBC36SAAN 0.2 S1011E-36-ND Sullins PBC36SAAN 0.1 SWITCHCRAFT Faston RIBBON6513O ICE Header UTLINE BLKCON.100/V H/TM2OE/W.2 HDR5X2 00/10 BLKCON.100/V HDR8X2 H/TM2OE/W.2 00/16 Ferrite Bead 600oh805 SC237-ND A24747CT-ND Switchcraft Inc.RAPC712X Tyco/AMP 62395-1 A33555-ND Tyco/AMP 5-104068-1 S2011E-36-ND Sullins PBC36DAAN 0.2 S2011E-36-ND Sullins PBC36DAAN 0.3 445-1556-1-ND TDK MMZ2012S601A 240-2546-1-ND Steward HI2220R181R-10 BC857CINCT-ND BCX70KINCT-ND Infineon TechnoBC857CE6327 Infineon BCX70KE6327XT SWITCHCRAFT Spade Terminal HI2220R181RFerrite Bead 180oh 10 SOT-23 BCE BC857 SOT-23 BCE BCX70 MOV CPS VARISTOR 2381594 1K 805 0 1206 603 0 100 805 100K 603 594-2381-59455116 541-1.0KACT-ND RHM0.0ECT-ND 541-0R0GCT-ND 541-100KACT-ND P100KGCT-ND AVX ±20% 10V ±10% 10V DNP 5A 2381 594 55116 Vishay/Dale CRCW08051K00JNEA Rohm SemicondMCR18EZHJ000 Vishay/Dale CRCW06030000Z0EA Vishay/Dale CRCW08051K00JNEA Panasonic ERJ-3GEYJ104V 5% 5% 5% 5% DNP Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 45 1 R6 8.20K 46 2 R7,R66 2M 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 3 3 1 1 1 3 1 1 1 1 4 3 4 1 1 2 5 2 2 R8,R106,R142 R9,R10,R11 R12 R13 R14 R15,R16,R17 R18 R19 R20 R21 R22,R26,R55,R57 R23,R32,R56 R24,R25,R33,R34 R27 R39 R47,R64 R74,R76,R103,R104,R105 R84,R85 R86,R87 1K 62 100K 20K 6.04K 62 30K 150 8.06K 25.2K 0 750 3.4 130 4.7K 270K 10K 10K 10K 66 1 R141 100 67 2 SW3,SW5 PB 68 1 TP2 TESTPOINT 69 1 TP3 TESTPOINT 70 1 T1 750-11-0056 71 72 73 74 75 76 77 78 1 1 1 1 1 1 1 1 U1 U2 U3 U4 U5 U8 U15 Y1 TL431 FT232RQ ADUM3201 SER EEPROM 71M6541 LCD VLS-6648 71M6601 32.768KHz 68 805 AXLE FLAME UPRIGHT 603 603 603 805 805 603 805 805 805 805 805 805 1206 1206 805 805 603 805 805 AXLE FLAME UPRIGHT PB TESTPOINTSMA LL BLKCON.100/V H/TM1SQ/W.1 00/1 XFORM/COMB O MID SO8-NARROW 32QFNW/GND SO8-NARROW SO8-NARROW LQFP-64 LCD VLS-6648 SOIC-8 XTAL-ECS-39 P8.20KCCT-ND Panasonic ERJ-6ENF8201V 1% 0.125W CMF2.00MHFCT-ND Vishay/Dale CMF552M0000FHEB 1% 0.5W P1.00KHCT-ND P62GCT-ND P62GCT-ND P20.0KCCT-ND 541-6.04KCCT-ND P62GCT-ND 311-30KARCT-ND RHM150CCT-ND RHM8.06KCCT-ND P25.5KCCT-ND RR12P750DCT-ND RR12P750DCT-ND 541-3.40CCT-ND 541-130FCT-ND RG20P4.7KBCT-ND RG20P270KBCT-ND P10.0KHCT-ND 541-10KACT-ND 541-10KACT-ND Vishay/Dale Panasonic Panasonic Panasonic Vishay/Dale Panasonic Yageo Rohm Rohm Panasonic Susumu Susumu Vishay/Dale Rohm TDK Susumu Panasonic Vishay/Dale Vishay/Dale ERJ-3EKF1001V ERJ-3GEYJ620V 100W-2-ND Yageo RSF200JB-100R P13598SCT-ND Panasonic EVQ-PNF05M 5011K-ND KEYSTONE 5011K-ND KEYSTONE 5011 Midcom 750-11-0056 296-1288-5-ND 768-1008-1-ND ADUM3201ARZ-ND AT24C1024BW-SH25-B-ND XC1658CT-ND ERJ-6ENF2002V CRCW08056K04FKEA ERJ-3GEYJ620V RC0805JR-0730KL MCR10EZHF1500 MCR10EZHF8061 ERJ-6ENF2552V RR1220P-751-D RR1220P-751-D CRCW08053R40FNEA CRCW1206130RFKEA RG2012P-472-B-T5 RG2012P-274-B-T5 ERJ-3EKF1002V CRCW080510K0JNEA CRCW080510K0JNEA 1% 5% 5% ±1% 125W, 1/8W ±1% 125W, 1/8W 5% 1W, 1/10W ±5% 125W, 1/8W ±1% 125W, 1/8W ±1% 125W, 1/8W ±1% 125W, 1/8W 1% 0.5% 1% ±1% 0.25W 0% 0% 1% 5% 5% 5% DNP DNP 2W 5011 DNP Texas Instrume TL431AIDR FTDI FT232RQ R Analog Devices ADUM3201ARZ ATMEL AT24C1024BN-SH25-B Teridian VARITRONIX VL_6648_V00 Teridian 71M6601 ECS ECS-.327-12.5-39-TR Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 4.3 71M6541-DB PCB LAYOUT Figure 4-3: 71M6541-DB REV 3.0: Top View 69 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual Figure 4-4: 71M6541-DB REV 3.0: Top Copper 70 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual Figure 4-5: 71M6541-DB REV 3.0: Bottom View 71 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual Figure 4-6: 71M6541-DB REV 3.0: Bottom Copper 72 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 4.4 71M6541 PINOUT INFORMATION Power/Ground/NC Pins: Table 4-2: 71M6541 Pin Description Table 1/3 Name Type GNDA GNDD P P V3P3A P V3P3SYS P V3P3D O VDD O VLCD O VBAT P VBAT_RTC P Description Analog ground: This pin should be connected directly to the ground plane. Digital ground: This pin should be connected directly to the ground plane. Analog power supply: A 3.3 V power supply should be connected to this pin. V3P3A must be the same voltage as V3P3SYS. System 3.3 V supply. This pin should be connected to a 3.3 V power supply. Auxiliary voltage output of the chip. In mission mode, this pin is connected to V3P3SYS by the internal selection switch. In BRN mode, it is internally connected to VBAT. V3P3D is floating in LCD and sleep mode. A bypass capacitor to ground should not exceed 0.1 µF. The output of the 2.5V regulator. This pin is powered in MSN and BRN modes. A 0.1 µF bypass capacitor to ground should be connected to this pin. The output of the LCD DAC. A 0.1 µF bypass capacitor to ground should be connected to this pin. Battery backup pin to support the battery modes (BRN, LCD). A battery or super-capacitor is to be connected between VBAT and GNDD. If no battery is used, connect VBAT to V3P3SYS. RTC and oscillator power supply. A battery or super-capacitor is to be connected between VBAT and GNDD. If no battery is used, connect VBAT_RTC to V3P3SYS. Analog Pins: Table 4-3: 71M6541 Pin Description Table 2/3 Name Type IAP/IAN, IBP/IBN, I VA I VREF O XIN XOUT I O Description Differential or single-ended Line Current Sense Inputs: These pins are voltage inputs to the internal A/D converter. Typically, they are connected to the outputs of current sensors. Unused pins must be tied to V3P3A. Pins IBP/IBN may be configured for communication with the remote sensor interface (71M6X0X). Line Voltage Sense Input: This pin is a voltage input to the internal A/D converter. Typically, it is connected to the output of a resistor divider. Unused pins must be tied to V3P3A. Voltage Reference for the ADC. This pin should be left unconnected (floating). Crystal Inputs: A 32 kHz crystal should be connected across these pins. Typically, a 15 pF capacitor is also connected from XIN to GNDA and a 10 pF capacitor is connected from XOUT to GNDA. It is important to minimize the capacitance between these pins. See the crystal manufacturer datasheet for details. If an external clock is used, a 150 mV (p-p) clock signal should be applied to XIN, and XOUT should be left unconnected. Pin types: P = Power, O = Output, I = Input, I/O = Input/Output 73 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual Digital Pins: Table 4-4: 71M6541 Pin Description Table 3/3 Name Type COM3,COM2, COM1,COM0 O SEGDIO0 … SEGDIO14, SEGDIO19 … SEGDIO25, SEGDIO44, SEGDIO45, I/O SEGDIO26/ COM5, SEGDIO27/ COM4 SEGDIO36/ SPI_CSZ, SEGDIO37/ SPI_DO, SEGDIO38/ SPI_DI, SEGDIO39/ SPI_CKI SEGDIO51/ OPT_TX, SEGDIO55/ OPT_RX E_RXTX/SEG48 E_RST/SEG50 E_TCLK/SEG49 I/O Description LCD Common Outputs: These 4 pins provide the select signals for the LCD display. Multi-use pins, configurable as either LCD segment driver or DIO. Alternative functions with proper selection of associated I/O RAM registers are: SEGDIO0 = WPULSE SEGDIO1 = VPULSE SEGDIO2 = SDCK SEGDIO3 = SDATA SEGDIO6 = XPULSE SEGDIO7 = YPULSE Unused pins must be configured as outputs or terminated to V3P3/GNDD. Multi-use pins, configurable as either LCD segment driver or DIO with alternative function (LCD common drivers). Multi-use pins, configurable as either LCD segment driver or DIO with alternative function (SPI interface). I/O I/O Multi-use pins, configurable as either LCD segment driver or DIO with alternative function (optical port/UART1) I/O I/O O Multi-use pins, configurable as either emulator port pins (when ICE_E pulled high) or LCD segment drivers (when ICE_E tied to GND). ICE_E I TMUXOUT/ SEG47, TMUX2OUT/ SEG46 O RESET I RX I TX O TEST I PB I ICE enable. When zero, E_RST, E_TCLK, and E_RXTX become SEG50, SEG49, and SEG48 respectively. For production units, this pin should be pulled to GND to disable the emulator port. Multi-use pins, configurable as either multiplexer/clock output or LCD segment driver using the I/O RAM registers. Chip reset: This input pin is used to reset the chip into a known state. For normal operation, this pin is pulled low. To reset the chip, this pin should be pulled high. This pin has an internal 30 μA (nominal) current source pulldown. No external reset circuitry is necessary. UART input. If this pin is unused it must be terminated to V3P3D or GNDD. UART output. Enables Production Test. This pin must be grounded in normal operation. Push button input. This pin must be at GNDD when not active or unused. A rising edge sets the IE_PB flag. It also causes the part to wake up if it is in SLP or LCD mode. PB does not have an internal pullup or pulldown resistor. Pin types: P = Power, O = Output, I = Input, I/O = Input/Output, 74 Rev 4.0 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 SPI_CKI/SEGDIO39 SEGDIO44 SEGDIO45 TMUX2OUT/SEG46 TMUXOUT/SEG47 RESET PB VLCD VREF IAP IAN V3P3A VA TEST GNDA XOUT 71M6541 Demo Board REV 3.0 User’s Manual 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Teridian 71M6541D 71M6541F 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 XIN VBAT_RTC VBAT V3P3SYS IBP IBN GNDD V3P3D VDD ICE_E E_RXTX/SEG48 E_TCLK/SEG49 E_RST/SEG50 RX TX OPT_TX/SEGDIO51 SEGDIO14 SEGDIO13 SEGDIO12 SEGDIO11 SEGDIO10 SEGDIO9 SEGDIO8/DI SEGDIO7/YPULSE SEGDIO6/XPULSE SEGDIO5 SEGDIO4 SEGDIO3/SDATA SEGDIO2/SDCK SEGDIO1/VPULSE SEGDIO0/WPULSE OPT_RX/SEGDIO55 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 SPI_DI/SEGDIO38 SPI_DO/SEGDIO37 SPI_CSZ/SEGDIO36 COM0 COM1 COM2 COM3 SEGDIO27/COM4 SEGDIO26/COM5 SEGDIO25 SEGDIO24 SEGDIO23 SEGDIO22 SEGDIO21 SEGDIO20 SEGDIO19 Figure 4-7: 71M6541, LQFP64: Pinout (Top View) 75 Rev 4.0 71M6541 Demo Board REV 3.0 User’s Manual 4.5 REVISION HISTORY REVISION DATE 2.0 1-14-2010 Initial release based on DBUM revision 1.1 for 6541 REV 1.0 Demo Board. 2.1 1-16-2010 Added Table 1-8 and explanation of scaling in CE and MPU codes. Added cautionary notes for connection of Line and Neutral. Updated formulae for WRATE and kh calculation. 76 DESCRIPTION Updated Figures 2-1, 2-2, and 2-3. Updated CLI tables and Bill of Material. Added chapter on temperature compensation. Removed most text referencing CTs and added notes stating that different Demo Code versions will be required for a CT configuration. Updated Demo Kit contents list. Updated Table 1-9. Added chapters on shunt self-heating and shunt placement. 2.2 1-29-2010 2.3 2-16-2010 2.4 3-5-2010 Corrected description of IMAX calculation. Added more information on selfheating. 2.5 6-3-2010 Added description of test and control commands for 71M6X0X Remote Sensor. Updated Demo Board schematics. Updated Demo Board top-level diagram (Figure 1.1). 2.6 8-16-2010 Added Figure 2.1 showing proper shunt connections. Corrected Figure 2.2. Added text in Application Section explaining the change from PHADJ_A to DLAYADJ_A compensation coefficients. Updated Calibration Spreadsheets. 3.0 5-10-2011 4.0 12/12 Updated schematics, PCB layout and BOM information to Demo Board Revision 3.0. Removed references to Debug Board. Added information on avoiding crosstalk between shunt resistors. Corrected equation for QUANT. Removed text stating that the Demo Code and documents/tools are delivered on a CD-ROM in the kit. Added attribute ‘optional’ for all references to the ‘Debug Board’. Added USB Interface Module as part of Demo Kit Contents. Updated sample images of calibration spreadsheets and added text stating that spreadsheets are available on the Maxim Integrated web site. Corrected part number for remote sensor IC (71M6601). Added sources for TPF2 Flash Programmer. Updated company logo. Replaced Teridian Semiconductor with Maxim Integrated where applicable. Rev 4.0