MAX16825EVKIT+

19-4052; Rev 0; 2/08 MAX16825 Evaluation Kit The MAX16825 evaluation kit (EV kit) demonstrates a high-voltage, 3-channel, linear high-brightness LED (HB LED) driver using the MAX16825 IC. This EV kit is configured to supply an LED current of 100mA per channel and operates from a 0.5A, 6.5V to 28V rated power supply. The MAX16825 EV kit uses a standard 4-wire SPI™ interface for independently controlling each of the three LED channels. The MAX16825 EV kit also integrates a USB-to-SPI interface circuit based on Maxim’s MAXQ2000 microcontroller. The EV kit includes Windows 2000/XP/Vista®-compatible software that provides a simple graphical user interface (GUI) for exercising the features of the MAX16825. The EV kit can also interface with a user-supplied SPI circuit for standalone operation. Features o Operates from a 6.5V to 28V, 0.5A Supply o 3 Channels for Driving High-Brightness LEDs o 100mA LED Current per Channel o Evaluates a Stand-Alone 4-Wire SPI Interface o USB-PC Interface (Cable Included) o Windows 2000/XP/Vista (32-Bit)-Compatible Software o Fully Assembled and Tested Ordering Information PART TYPE MAX16825EVKIT+ EV Kit +Denotes lead-free and RoHS-compliant. Component List DESIGNATION C1, C3–C10, C17 QTY 10 C2, C13, C15 3 C11, C12 2 C14, C16, C22 3 C18, C19 2 C20 1 C21 1 DESCRIPTION 0.1µF ±10%, 16V X7R ceramic capacitors (0603) TDK C1608X7R1C104K 10µF ±20%, 6.3V X5R ceramic capacitors (0805) TDK C2012X5R0J106M 10pF ±5%, 50V C0G ceramic capacitors (0603) TDK C1608C0G1H100J 1µF ±10%, 10V X5R ceramic capacitors (0603) Murata GRM188R61A105K 22pF ±5%, 50V C0G ceramic capacitors (0603) TDK C1608C0G1H220J 3300pF ±10%, 50V X7R ceramic capacitor (0603) TDK C1608X7R1H332K 1µF ±10%, 50V X7R ceramic capacitor (1210) Murata GRM32ER71H105K or TDK C3325X7R1H105K DESIGNATION QTY D1 1 FB1 0 H1, J1 0 J2 0 P1 1 R1 R2 R3 R4 R5 R6, R7 1 1 1 1 1 2 R8, R9, R10 3 R11 0 DESCRIPTION Green LED (0603) Panasonic LNJ314G8TRA Not installed, ferrite-bead inductor (0603) Not installed, dual-row (2 x 5) 10pin headers Not installed, dual-row (2 x 4) 8pin header USB type-B right-angle female receptacle 0Ω ±5% resistor (0603) 220Ω ±5% resistor (0603) 10kΩ ±5% resistor (0603) 2.2kΩ ±5% resistor (0603) 1.5kΩ ±5% resistor (0603) 27Ω ±5% resistors (0603) 2Ω ±1%, 0.25W sense resistors (1206) IRC WCR-WCR1206LF-2R00-F Not installed, resistor (0402) SPI is a trademark of Motorola, Inc. Windows Vista is a registered trademark of Microsoft Corp. ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com. 1 Evaluates: MAX16825 General Description MAX16825 Evaluation Kit Evaluates: MAX16825 Component List (continued) DESIGNATION U1 QTY 1 DESCRIPTION SPI-controlled linear HB LED driver (16-pin TSSOP-EP*) Maxim MAX16825AUE+ SUPPLIER PHONE WEBSITE IRC, Inc. 361-992-7900 www.irctt.com Murata Mfg. Co., Ltd 770-436-1300 www.murata.com 1 Low-power 16-bit microcontroller (68-pin QFN-EP*, 10mm x 10mm) Maxim MAXQ2000-RAX+ Panasonic 800-344-2112 www.panasonic.com TDK Corp. 847-803-6100 www.component.tdk.com U3 1 93C46 type 3-wire EEPROM (8-pin SO) Note: Indicate that you are using the MAX16825 when contacting these component suppliers. U4 1 UART-to-USB converter (32-pin TQFP, 7mm x 7mm) 1 3.3V regulator (5-pin SC70) Maxim MAX8511EXK33+T (Top Mark: AEI) 1 2.5V regulator (5-pin SC70) Maxim MAX8511EXK25+T (Top Mark: ADV) U2 U5 U6 Y1 1 16MHz crystal Y2 1 6MHz crystal — 1 USB high-speed A-to-B cable, 6ft — 1 PCB: MAX16825 Evaluation Kit+ *EP = Exposed paddle. Quick Start Required Equipment Before beginning, the following equipment is needed: • MAX16825 EV kit (USB cable included) • 6.5V to 28V, 0.5A adjustable DC power supply • User-supplied Windows 2000/XP/Vista PC with a spare USB port • Three LED loads, each rated as follows: Current rating ≥ 100mA Total LED string forward voltage VFLED ≤ 26.3V • See the LED Load Configuration section for more information Note: In the following sections, software-related items are identified by bolding. Text in bold refers to items directly from the EV kit software. Text in bold and underlined refers to items from the Windows operating system. Procedure The MAX16825 EV kit is fully assembled and tested. Follow the steps below to verify board operation. Caution: Do not turn on the power supply until all connections are completed. 2 Component Suppliers MAX16825 EV Kit Files FILE INSTALL.EXE DESCRIPTION Installs the EV kit files on your computer MAX16825.EXE Application program FTD2XX.INF USB device driver file UNINST.INI Uninstalls the EV kit software TROUBLESHOOTING_USB.PDF USB driver installation help file 1) Visit www.maxim-ic.com/evkitsoftware to download the latest version of the EV kit software, 16825Rxx.ZIP. Save the EV kit software to a temporary folder and uncompress the ZIP file. 2) Install the EV kit software on your computer by running the INSTALL.EXE program inside the temporary folder. The program files are copied and icons are created in the Windows Start | Programs menu. All EV kit files are automatically installed. 3) Set the power-supply output to over VFLED + 1.7V. 4) Disable the power-supply output. 5) Connect the power-supply ground to the GND pad next to the VIN pad. 6) Connect the power-supply positive output to the VIN pad. 7) Connect one LED load anode to each LED output pad (LED1+, LED2+, or LED3+). 8) Connect each LED load cathode to the corresponding LED input pad (LED1-, LED2-, or LED3-). 9) Connect the USB cable from the PC to the EV kit board. A New Hardware Found window pops up when installing the USB driver for the first time. If you do not see a window that is similar to the one _______________________________________________________________________________________ MAX16825 Evaluation Kit 12) Start the EV kit software by opening its icon in the Start | Programs menu. The MAX16825 EV kit software main window appears, as shown in Figure 1. 13) Select the Output Enable checkbox and any of the Channel_ checkboxes. 14) Verify that the corresponding attached LEDs are illuminated. The software features a demo mode that is available by selecting the View | Demo Mode menu item. When operating in demo mode, all software communication to the EV kit hardware is disabled and most of the software’s GUI is functional. This feature enables the user to evaluate the software without hardware connectivity. The left-bottom status bar provides the USB-to-SPI communication status. The right-bottom status bar provides the current program status. The MAX16825 EV kit software configures the on-board SPI communication to 8kHz by default. Software Startup Upon starting the program, select the Output Enable checkbox to enable the LED outputs. Deselecting the Output Enable checkbox disables all three LED outputs. The Channel_ checkboxes enable and disable individual channels. General-Purpose 3-Wire (SPI) Interface Utility The general-purpose 3-wire interface utility (Figure 2) can also be used to communicate with the MAX16825 using low-level SPI commands. Select the Options | Interface menu item and select the 3-wire interface tab to access the utility. The utility configures the 3-wire serial-interface parameters, such as MSB position, CPOL, CPHA, MOSI/MISO inverted logic, CS active state (high or low), SPI clock (SCLK) speed, and custom selection of SPI signal pins. The data to be sent is 8-bit data represented by a two-digit hexadecimal code. The code is entered in the Data bytes to be written edit box and transmitted by clicking on the Send Now button. General Troubleshooting Problem: Software reports it cannot find the interface circuit. • Is power LED D1 lit? Figure 1. MAX16825 Evaluation Kit Software—Graphical User Interface (GUI) Detailed Description of Software Graphical User Interface The main window’s GUI (Figure 1) is simple to use. A mouse or the keyboard’s tab key is used to navigate through the controls. The correct SPI write operation is generated to update the internal registers of the MAX16825 when any of these controls are used. • Is the USB cable connected to the PC and EV kit? • Is power applied to the VIN PCB pad? • Has Windows plug-and-play detected the board? Bring up the Control Panel > System > Device Manager, and look at what device nodes are indicated for USB. If there is an unknown device node attached to the USB, delete it. This process forces plug-and-play to try again. _______________________________________________________________________________________ 3 Evaluates: MAX16825 described above after 30s, remove the USB cable from the board and reconnect it. Administrator privileges are required to install the USB device driver on Windows. 10) Follow the directions of the Add New Hardware Wizard to install the USB device driver. Choose the Search for the best driver for your device option. Specify the location of the device driver to be C:\Program Files\MAX16825 (default installation directory) using the Browse button. During device driver installation, Windows may show a warning message indicating that the device driver Maxim uses does not contain a digital signature. This is not an error condition and it is safe to proceed with installation. Refer to the TROUBLESHOOTING_USB.PDF document included with the software for additional information. 11) Enable the power-supply output. Evaluates: MAX16825 MAX16825 Evaluation Kit Figure 2. The 3-Wire Interface Window Provides Direct, Low-Level Access to the MAX16825 and 3-Wire Serial Interface 4 _______________________________________________________________________________________ MAX16825 Evaluation Kit The MAX16825 EV kit demonstrates a high-voltage, 3channel, linear high-brightness LED driver using the MAX16825 IC in a 16-pin TSSOP surface-mount package. This EV kit is configured to supply an LED current of 100mA per channel. The MAX16825 IC controls the LED current by maintaining a 200mV drop across each external sense resistor (R8, R9, and R10). The EV kit operates from a 0.5A, 6.5V to 28V rated power supply. The MAX16825 EV kit uses a standard 4-wire SPI interface for independently controlling each of the three individual channels. Only the components in the Figure 3 schematic are required when using a user-supplied SPI interface. The MAX16825 integrates a USB-to-SPI interface circuit that is based on Maxim’s MAXQ2000 16-bit microcontroller. The EV kit includes Windows 2000/XP/Vista-compatible software that provides a GUI for exercising the MAX16825 features. The components on the Figure 4 schematic are only required for PC evaluation and are not needed for an HB LED design. The MAX16825 features an exposed paddle that uses the top-layer and bottom-layer PCB copper as a heatsink. The exposed paddle connects to GND. LED Load Configuration The MAX16825 EV kit can drive three separate LED loads. Each LED load can consist of multiple LEDs connected in series. The LED load’s forward voltage can be up to 26.3V. The EV kit drives LEDs rated for at least 100mA. Proper heat sinking of the LEDs is important for optimum LED performance and durability. Output Current Setting The current for each MAX16825 EV kit LED channel (ILED1, ILED2, and ILED3) is configured to 100mA by three sense resistors (R8, R9, and R10, respectively). See the equation below to select a different LED current and a new resistor value. If designing for a higher LED current, verify that the desired current setting does not exceed the power rating of the corresponding resistor (R8, R9, R10) or the LED load. Do not set the LED current above 150mA. Use the following equation to calculate the value of the new resistor: R_ = 200mV ILED _ where ILED_ is the desired LED current and R_ is the resistor value required to set the desired current of the LED channel. _______________________________________________________________________________________ 5 Evaluates: MAX16825 Detailed Description of Hardware Evaluates: MAX16825 MAX16825 Evaluation Kit High Input Voltage and Thermal Protection User-Supplied SPI Interface The user may control the MAX16825 EV kit directly with a user-supplied, 5V logic, 4-wire SPI interface for standalone operation. Cut open header J2’s shorting traces located on the PCB’s bottom layer. Connect the user-supplied CS, SCLK, DIN, and a control signal to the OE, CLK, DIN, and LE pads, respectively, on the MAX16825 EV kit. Refer to the Electrical Characteristics, SPI Interface section of the MAX16825 IC data sheet for more information on the MAX16825’s SPI communication requirements. The MAX16825 IC operates in linear mode. As a result, the IC can dissipate significant power if operated using a high input voltage and a small VFLED. High-power dissipation may cause the IC to go into thermal shutdown. Refer to the Thermal Protection section in the MAX16824/ MAX16825 IC data sheet for more information. VIN LED1+ VIN LED2+ GND C21 1μF LED3+ GND 3 GND IN 7 DIN DIN 8 LE LE 9 OE OE 10 DOUT 6 CLK CLK 4 VREG GND C22 1μF OUT1 DIN U1 LE OUT2 MAX16825 OUT3 OE DOUT CS1 CLK CS2 REG CS3 N.C. N.C. GND 5 14 11 1 LED1- 16 LED2- 12 LED3- 2 15 13 R10 2Ω 1% R9 2Ω 1% R8 2Ω 1% Figure 3. MAX16825 EV Kit Schematic—LED Driver Circuit 6 _______________________________________________________________________________________ 6 5 +5V C17 0.1μF C16 1μF +5V 3 1 U5 OUT GND N.C. ORG VCC SHDN GND 2 5 DO D1 SK CS U3 AT93C46A 4 MAX8511 5 7 6 8 GND IN 2 1 D+ 3 D- VBUS USB TYPE B SHIELD SHIELD P1 1 IN 32 28 27 4 +3.3V 4 C15 10μF R3 10kΩ +5V 3 C14 1μF SHDN 2 5 TEST +2.5V EEDATA EESK EECS XTOUT XTIN RESET RSTOUT USBDP USBDM GND MAX8511 U6 OUT 31 2 +5V 5 7 8 6 AVCC 3V3OUT 3 C13 10μF 29 AGND VCC TDI H1-10 H1-9 OPEN H1-2 H1-8 H1-7 H1-5 H1-6 TMS H1-4 H1-3 10 H1-1 H1 JTAG SLEEP PWREN 15 14 11 12 16 18 19 20 21 22 23 24 TCK 17 GND PWRCTL RXLED TXLED TXDEN RI DCD DSR DTR CTS RTS RXD 13 VCCIO 25 TXD +3.3V R2 220Ω RI DCD DSR DTR CTS RTS RXD TXD RESET D1 DTR RTS RI DIN LE OE J2-5 J2-3 J2-1 J2-6 J2-4 J2-2 SS U1_64 SHORT CLK J2-7 J2-8 SCLK MOSI HEADER 2x4 J2 SHORT 62 23 DSR 22 DCD 21 J1-8 20 63 J1-10 J1-6 J1-4 J1-2 19 64 J1-9 J1-5 J1-3 J1-1 HEADER 2x5 J1 18 65 J1-7 GND GND SEG27/P3.3 SEG26/P3.2 SEG25/P3.1 SEG24/P3.0 SEG23/P2.7 SEG22/P2.6 SEG21/P2.5 SEG20/P2.4 SEG19/P2.3 SEG18/P2.2 SEG17/P2.1 SEG16/P2.0 SEG15/P1.7 SEG14/P1.6 SEG13/P1.5 SEG12/P1.4 SEG11/P1.3 VDD 66 TDI 42 28 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 49 SEG9/P1.1 TCK TMS TDO RESET +3.3V C9 0.1μF +2.5V SEG10/P1.2 67 SEG30/P3.6/INT6 68 SEG8/P1.0 SEG28/P3.4/INT4 C8 0.1μF SEG34/COM2 24 61 25 60 U2 MAXQ2000 26 59 58 SEG0/P0.0 SEG1/P0.1 +3.3V TDO 9 GND U4 FT232BL VCC 26 C7 0.1μF SEG7/P0.7/INT3 SEG29/P3.5/INT5 +5V SEG6/P0.6/INT2 SEG31/P3.7/INT7 30 C6 0.1μF SEG5/P0.5/INT1 SEG32 +5V SEG4/P0.4/INT0 SEG33/COM3 C5 0.1μF 57 VADJ TCK 29 P4.0/TCK/INT8 R1 0Ω 56 VLCD2 TDI 30 P4.1/TDI/INT9 C4 0.1μF 3 +5V C18 22pF Y2 6MHz C19 22pF +5V 1 R4 2.2kΩ R5 1.5kΩ C20 3300pF C3 0.1μF 2 1 R6 27Ω R7 27Ω C2 10μF 55 VLCD1 TMS 31 P4.2/TMS 54 53 52 RXD P6.5/TO/WKOUT 1 HFXOUT HFXIN VDDIO 32KOUT 32KIN P5.2/RX1/INT10 P5.3/RX1/INT11 P5.4/SS P5.5/MOSI P5.6/SCLK P5.7/MISO P6.0/T1B/INT12 P6.1/T1/INT13 P6.2/T2B/OW_OUT P6.3/T2/OW_IN P6.4/TOB/WKOUT 0 TXD TDO RESET 32 33 +3.3V VLCD P4.3/TD0 FB1 SHORT SEG3/P0.3 SEG35/COM1 C1 0.1μF SEG2/P0.2 COM0 P7.0/TXO/INT14 U1_64 P7.1/RXO/INT15 RESET 35 34 36 37 38 39 40 41 43 44 45 46 47 48 50 51 27 RTS DTR SS MOSI SCLK R11 OPEN C12 10pF C11 10pF Y1 16MHz +3.3V C10 0.1μF CTS DSR Evaluates: MAX16825 +5V MAX16825 Evaluation Kit Figure 4. MAX16825 EV Kit Schematic—USB and SPI Interface Circuit _______________________________________________________________________________________ 7 Evaluates: MAX16825 MAX16825 Evaluation Kit Figure 5. MAX16825 EV Kit Component Placement Guide—Component Side 8 _______________________________________________________________________________________ MAX16825 Evaluation Kit Evaluates: MAX16825 Figure 6. MAX16825 EV Kit PCB Layout—Component Side _______________________________________________________________________________________ 9 Evaluates: MAX16825 MAX16825 Evaluation Kit Figure 7. MAX16825 EV Kit PCB Layout—Solder Side Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 10 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2008 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc. Boblet