1FEATURES
234• 24-CHANNEL GAMMA
– 22-CHANNEL PROGRAMMABLE
– 2-CHANNEL STATIC GAMMA
• 2-CHANNEL PROGRAMMABLE VCOM • 10-BIT RESOLUTION
• 16x REWRITABLE NONVOLATILE MEMORY
• TWO INDEPENDENT MEMORY BANKS
• RAIL-TO-RAIL OUTPUT
• LOW SUPPLY CURRENT: 0.5mA/channel
• SUPPLY VOLTAGE: 9V to 20V
• DIGITAL SUPPLY: 2V to 5.5V
• I2C™ INTERFACE

APPLICATIONS
• TFT-LCD REFERENCE DRIVERS

DESCRIPTION
The BUF22821 offers 22 programmable gamma
channels, two programmable VCOM channels, and two
static gamma channels. It is ideal for the new 10-bit
source drivers that require 22 gamma channels.
The final gamma and VCOM values can be stored in the on-chip, nonvolatile memory. To allow for
programming errors or liquid crystal display (LCD)
panel rework, the BUF22821 supports up to 16 write
operations to the on-chip memory. The BUF22821
has two separate banks of memory, allowing
simultaneous storage of two different gamma curves
to facilitate switching between gamma curves.
All gamma and VCOM channels offer a rail-to-rail output that typically swings to within 100mV of either
supply rail with a 10mA load. All channels are
programmed using an I2C interface that supports
standard operations up to 400kHz and high-speed
data transfers up to 3.4MHz.
The BUF22821 is manufactured using Texas
Instruments’ proprietary, state-of-the-art, high-voltage
CMOS process. This process offers very dense logic
and high supply voltage operation of up to 20V. The
BUF22821 is offered in a HTSSOP-38 PowerPAD™
package. It is specified from –40°C to +85°C.