SBOS399D – JUNE 2007 – REVISED JULY 2011
Programmable Gamma-Voltage Generator and
VCOM Calibrator with Integrated Two-Bank Memory
Check for Samples: BUF22821
•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
• TFT-LCD REFERENCE DRIVERS
(2.0V to 5.5V) (9V to 20V)
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.
12-Channel Gamma Correction Buffer
20-Channel Programmable Buffer, 10-Bit, VCOM
16-/20-Channel Programmable Buffer with Memory
Programmable VCOM Driver
18V Supply, Traditional Gamma Buffers
22V Supply, Traditional Gamma Buffers
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PowerPAD is a trademark of Texas Instruments.
I2C is a trademark of NXP Semiconductors.
All other trademarks are the property of their respective owners.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2007–2011, Texas Instruments Incorporated