Digitally Programmable LCD Gamma Reference Generator with Digital Voltage Reference

The MAX5679 digitally programmable LCD gamma reference generator provides 18 buffered channels for biasing LCD column drivers. The device provides 14 outputs of 8-bit programmable gamma reference voltage derived from four externally applied reference voltages, and four buffered outputs of the same externally applied reference voltages. An I²C serial interface programs the 14 upper and lower range gamma buffer outputs independently.

The MAX5679 features a digitally programmable voltage reference (DVR) with 7-bit adjustable current sink to set the LCD common backplane (VCOM) voltage. The MAX5679 includes a power-on reset (POR) function that configures all 14 programmable gamma outputs to predetermined levels upon initial power-up.

The MAX5679 is available in a 5mm x 5mm, 32-pin TQFN package and is specified over the -40°C to +85°C extended temperature range.

Applications

* TFT-LCD Panels for Desktop Monitors * TFT-LCD Panels for Flat Screen TVs

* 7-Bit Adjustable VCOM Calibrator (DVR)

* 14 Programmable Gamma Outputs for LCD

* Column Driver ICs

* 8-Bit DAC Resolution for Upper and Lower Range Outputs

* Maximum Output Swing of (AVDD - 0.2V) (OUT1–OUT7)

* Minimum Output Swing of (GND + 0.2V) (OUT8–OUT14)

* Four Independent Reference Inputs

* Four Independent Buffered Reference Outputs

* 9V to 20V Analog Supply

* 2V to 5.5V Digital Supply

* 400kHz I²C-Compatible Serial Interface

* Pin-Selectable I²C Address Bit Allows Two Slave IDs

* Backward Compatible with the MAX5678