19-3624; Rev 0; 3/05
EEPROM-Programmable TFT VCOM
Calibrator with I2C Interface
The MAX8738 is an I2C-programmable VCOM-adjust-
ment solution for thin-film transistor (TFT) liquid-crystal
displays (LCDs). The MAX8738 simplifies the labor-inten-
sive VCOM-adjustment process and replaces mechani-
cal potentiometers, which significantly reduces labor
costs, increases reliability, and enables automation.
The MAX8738 attaches to an external resistive voltage-
www.DataSheedt4iUv.icdoemr and sinks a programmable current to set the
VCOM voltage level. An internal 7-bit digital-to-analog
converter (DAC) controls the sink current. The DAC is
ratiometric relative to AVDD and is guaranteed to be
monotonic over all operating conditions. This VCOM
calibrator IC includes an EEPROM to store the desired
VCOM voltage level. The EEPROM can be programmed
repeatedly, giving TFT LCD manufacturers the flexibility
to calibrate the display panel as many times as the
manufacturing process requires.
The MAX8738 features a 2-wire I2C* interface for DAC-
adjustment commands and EEPROM programming.
The interface utilizes the existing I2C bus on the LCD
panel connector so no additional panel connector pins
are required. The MAX1512 is a similar product with a
1-wire interface and is recommended for applications
with no existing I2C interface.
The MAX8738 is available in an 8-pin µMAX® package.
A complete evaluation kit is available to simplify evalua-
tion and production development.
♦ 7-Bit Adjustable Sink-Current Output
♦ Resistor-Adjustable, Full-Scale Range
♦ Guaranteed Monotonic Output Over Operating
♦ 2-Wire I2C Interface
♦ EEPROM Stores VCOM Setting
♦ 4.5V to 20V Analog Supply Voltage Range
♦ 60µA (max) AVDD Supply Current
♦ 16.1V to 28V EEPROM Programming Supply
Voltage Range (VHV)
♦ <1µA HV Supply Current (Not in Program Mode)
♦ 8-Pin µMAX
-40oC to +85oC
-40oC to +85oC
+Denotes lead-free package.
µMAX is a registered trademark of Maxim Integrated Products, Inc.
Typical Operating Circuit
VDD HV AVDD
Purchase of I2C components from Maxim Integrated Products,
Inc., or one of its sublicensed Associated Companies, conveys
a license under the Philips I2C Patent Rights to use these com-
ponents in an I2C system, provided that the system conforms
to the I2C Standard Specification as defined by Philips.
________________________________________________________________ Maxim Integrated Products 1
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.