12-Channel Programmable Gamma Reference System

The MAX9697 12-channel programmable gamma reference system provides 12 programmable reference voltages with 10-bit resolution. These voltages can be used for gamma correction in TFT-LCD displays, as a VCOM reference, or as sources for level shifter inputs. Each reference voltage features a 10-bit digital-to-analog converter (DAC) and buffer with high peak current to reduce the recovery time of the output voltages when critical levels and patterns are displayed.

An adjustable, low-dropout linear regulator (LDO) further improves the stability and accuracy of the DAC outputs by creating the DAC reference. The MAX9697's integrated gate-driver output controls an external p-channel FET to slowly turn on the linear regulator so that the reference voltages ramp up in a controlled manner.

The MAX9697 has a serial peripheral interface (SPI™) bus for programming the reference voltages. The device also has a current-sense comparator to detect an abnormally high supply current in other areas of the application circuit.

The MAX9697 is available in a 28-pin TQFN package and is specified for operation over the -40°C to +125°C temperature range.

Applications

* TFT-LCD Panels

* 12 Programmable Reference Voltages with 10-Bit Resolution

* Controlled Ramp-Up of Reference Voltages

* Adjustable LDO

* Current-Sense Comparator

* 10V to 18V Analog Supply Range

* 2.3V to 3.6V Digital Supply Range

* SPI Interface