MAX8738EVKIT

19-3658; Rev 0; 5/05 MAX8738 Evaluation Kit The MAX8738 evaluation kit (EV kit) is a fully assembled and tested circuit board that evaluates the MAX8738 programmable VCOM-adjustment solution for thin-film transistor (TFT), liquid-crystal displays (LCDs). The EV kit is designed to be used as a replacement for the labor-intensive VCOM-adjustment process usually done by setting potentiometers mechanically. The EV kit includes an optical encoder and a pushbutton that are used to adjust the VCOM voltage and save this voltage setting into the MAX8738’s internal EEPROM. Features ♦ Proven PC Board Layout ♦ Optical Encoder for Easy VCOM Adjustments ♦ Restores VCOM Settings on Power-Up ♦ Momentary Pushbutton for Internal EEPROM Programming ♦ LEDs for User Feedback ♦ Terminals for External I2C Bus Control ♦ Fully Assembled and Tested Ordering Information PART TEMP RANGE MAX8738EVKIT 0°C to +70°C IC PACKAGE 8 µMAX Component List DESIGNATION C1 C2–C9 C10 QTY DESCRIPTION 1 0.01µF ±10%, X7R 50V capacitor (0603) TDK C1608X7R1H103K 8 0.1µF ±10%, X7R 50V capacitors (0603) TDK C1608X7R1H104K 1 10µF ±20%, 10V capacitor (1206) TDK X5R C3216X5R1A106M C11 1 2.2µF ±10%, X7R 25V capacitor (1206) TDK C3216X7R1E225K C12, C13 2 18pF ±5%, 50V C0G capacitors (0603) TDK C1608C0G1H180J D1–D4 4 Green LEDs Kingbright L934GT J1 1 2 x 5 right-angle receptacle (2mm) Sullins PPWN052FJFN R1, R2 2 3.9kΩ ±5% resistors (0603) R3 1 24.9kΩ ±1% resistor (0805) R4 1 51.1kΩ ±1% resistor (0805) R5 1 64.9kΩ ±1% resistor (0805) R6, R7 2 8.2kΩ ±5% resistors (0603) DESIGNATION R8–R11 QTY 4 DESCRIPTION 150Ω ±5% resistors (0603) R12–R15 4 10kΩ ±5% resistors (0603) R16 1 10Ω ±5% resistor (0603) SW1 1 32-position optical encoder Grayhill 61C11-01-08-01 SW2 1 Momentary pushbutton switch OMRON B3S-1000 U1 1 TFT LCD calibrator (I2C interface) MAX8738EUA (8-pin µMax) U2 1 Ultra-high-speed microcontroller DS89C420-ECL (44-pin TQFP) U3 1 300mA, LDO, 3.3V regulator MAX8887EZK33-T (5-pin SOT23) Y1 1 6MHz crystal Citizen HC49US6.000MABJ None 1 MAX8738 EV kit PC board ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 Evaluates: MAX8738 General Description Evaluates: MAX8738 MAX8738 Evaluation Kit Component Suppliers SUPPLIER PHONE WEBSITE Citizen 949-428-3700 www.citizencrystal.com TDK 847-803-6100 www.component.tdk.com Note: Indicate you are using the MAX8738 when contacting these component suppliers. Quick Start Recommended Equipment • 3 power supplies: a) 16.1V or higher (up to 28V) at 10mA for VGON b) 9V at 10mA for AVDD c) 5V at 250mA for VCC • 1 digital voltmeter (DVM) Procedure Do not turn on the power supplies until all connections are made: 1) Connect the 5V power supply between the VCC and GND pads. 2) Connect the 16.1V or higher power supply between the VGON and GND pads. 3) Connect the 9V power supply between the AVDD and GND pads. 4) Turn on all three power supplies. 5) Measure the voltage at VOUT. It should be approximately 3.73V. Detailed Description The MAX8738 evaluation kit (EV kit) is a fully assembled and tested circuit board that evaluates the MAX8738 programmable VCOM-adjustment solution for TFT LCDs. On the PC board, the unbuffered VCOM adjustment signal (VOUT) is available on the VOUT pad. 2 The EV kit is designed to output a typical VOUT voltage between 3.48V and 3.97V (with AVDD at 9V) with 7-bit resolution. For this, the AVDD voltage should be 9V. If a different VOUT range is desired or if a different AVDD voltage is used, the user may need to change R3, R4, and R5. The pads for these resistors are designed for standard 0805 case sizes. Refer to the Setting the VCOM Adjustment Range section in the MAX8738 data sheet for instructions about how to select these resistors. Note that the VGON input voltage must be between 16.1V and 28V to supply the high voltage needed for internal EEPROM programming. An optical encoder (SW1) is used to send VCOM adjustment commands to the MAX8738. When the user turns the knob on the optical encoder, the on-board microcontroller (U2) sends an I2C command byte (0xFF or 0x00) to the MAX8738. Turning the knob clockwise decreases the VOUT voltage, while turning the knob counterclockwise increases the VCOM voltage. As the knob on the optical encoder is turned, a different LED lights indicating the direction of change of the VOUT voltage. The momentary pushbutton switch (SW2) on the EV kit is used to save the MAX8738’s DAC setting to its internal EEPROM. When the button is pressed, the on-board microcontroller (U2) sends an I 2 C command byte (0xAA) to the MAX8738. The LEDs flash on and off quickly, indicating that the DAC setting has been saved. The MAX8738 supports additional I2C command bytes not supported by this EV kit such as 0x55 (reload DAC setting from EEPROM) and 0x11 (program-specific value of the DAC). The SDA and SCL pads on the EV kit can be used to connect to an I 2C controller where these commands (or any of the commands supported by the MAX8738) can be transmitted. _______________________________________________________________________________________ MAX8738 Evaluation Kit VCC J1* R5 64.9kΩ 1% VOUT RXDO EA PSEN SW1 J1–1 J1–2 J1–3 J1–4 J1–5 J1–6 J1–7 J1–8 J1–9 J1–10 R4 51.1kΩ 1% TXDO VCC RST R7 8.2kΩ RST R14 VCC 10kΩ VCC 5 RXDO C3 0.1µF 6 UNUSED SW2 7 TXDO R13 10kΩ R16 10Ω P0.2 35 P0.3 34 36 P0.1 P0.0 37 38 VCC P0.6 P3.0 P0.7 U2 DS89C420 VCC EA/VPP GND ALE/PROG 8 C8 0.1µF R8 150Ω D1 33 R9 150Ω D2 32 R10 150Ω D3 31 R11 150Ω D4 30 29 28 EA R12 10kΩ VCC P3.1 P3.2 PSEN P3.3 10 P3.4 11 P3.5 P2.7 9 C13 18pF P2.6 P2.5 27 26 PSEN 25 24 23 UNUSED Y1 6MHz UNUSED P2.3 22 P2.4 VCC 3 P1.7 4 RST P2.2 C1 0.01µF P0.4 P0.5 P2.1 BP 3.3V UNUSED P1.6 20 GND 2 ENCOUTB 4 1 R1 3.9kΩ SDA SCL 19 SHDN 2 P2.0 3 P1.5 GND MAX8887 1 ENCOUTA C11 2.2µF 17 C9 0.1µF GND 39 5 16 OUT XTAL1 U3 15 R15 10kΩ IN 44 3.3V 1 P1.0 40 UNUSED P1.1 41 C7 0.1µF R2 3.9kΩ C2 VCC 0.1µF 18 GND C4 0.1µF GND AVDD 4 XTAL2 AVDD C5 0.1µF R3 24.9kΩ 1% 14 2 VDD 2 3.3V 3 42 AVDD VCC HV MAX8738 P1.2 C6 0.1µF 3 8 P3.7 5 SET 43 VGON 16V TO 28V VGON SDA U1 4 1 P1.3 6 OUT 13 SDA SDA SCL P1.4 7 12 P3.6 SCL 5 ENCOUTA ENCOUTB SCL 6 R6 8.2kΩ 21 C10 10µF GND Evaluates: MAX8738 AVDD VCC +5V VCC C12 18pF *J1 IS USED FOR FACTORY PROGRAMMING OF U2. Figure 1. MAX8738 EV Kit Schematic _______________________________________________________________________________________ 3 Evaluates: MAX8738 MAX8738 Evaluation Kit Figure 2. MAX8738 EV Kit Component Placement Guide— Component Side Figure 3. MAX8738 EV Kit PC Board Layout—Component Side Figure 4. MAX8738 EV Kit PC Board 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. 4 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc. Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Maxim Integrated: MAX8738EVKIT