BUF22821

STATOUTH

AVDD

STATINH

Analog

(9Vto20V)

Digital

(2.0Vto5.5V)

BKSEL

A0

SCL

SDA

V

COM2

V

COM1

ControlIF

OUT21

OUT22

BUF22821

OUT1

OUT2

STATOUTL

AVDD

STATINL

1

BUF22821

www.ti.com

SBOS399D

– JUNE 2007 – REVISED JULY 2011

Programmable Gamma-Voltage Generator and

VCOM Calibrator with Integrated Two-Bank Memory

Check for Samples: BUF22821

1

FEATURES

DESCRIPTION

The BUF22821 offers 22 programmable gamma

234

•

24-CHANNEL GAMMA

channels, two programmable VCOM channels, and two

– 22-CHANNEL PROGRAMMABLE

static gamma channels. It is ideal for the new 10-bit

– 2-CHANNEL STATIC GAMMA

source drivers that require 22 gamma channels.

•

2-CHANNEL PROGRAMMABLE VCOM

The final gamma and VCOM values can be stored in

•

10-BIT RESOLUTION

the

on-chip,

nonvolatile

memory.

To

allow

for

•

16x REWRITABLE NONVOLATILE MEMORY

programming errors or liquid crystal display (LCD)

•

TWO INDEPENDENT MEMORY BANKS

panel rework, the BUF22821 supports up to 16 write

operations to the on-chip memory. The BUF22821

•

RAIL-TO-RAIL OUTPUT

has

two

separate

banks

of

memory,

allowing

•

LOW SUPPLY CURRENT: 0.5mA/channel

simultaneous storage of two different gamma curves

•

SUPPLY VOLTAGE: 9V to 20V

to facilitate switching between gamma curves.

•

DIGITAL SUPPLY: 2V to 5.5V

All gamma and VCOM channels offer a rail-to-rail

•

I2C

™ INTERFACE

output that typically swings to within 100mV of either

supply rail with a 10mA load. All channels are

APPLICATIONS

programmed using an I2C interface that supports

standard operations up to 400kHz and high-speed

•

TFT-LCD REFERENCE DRIVERS

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.

RELATED PRODUCTS

FEATURES

PRODUCT

12-Channel Gamma Correction Buffer

BUF12800

20-Channel Programmable Buffer, 10-Bit, VCOM

BUF20800

16-/20-Channel Programmable Buffer with Memory

BUF20820

Programmable VCOM Driver

BUF01900

18V Supply, Traditional Gamma Buffers

BUF11704

22V Supply, Traditional Gamma Buffers

BUF11705

1

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.

2

PowerPAD is a trademark of Texas Instruments.

3

I2C is a trademark of NXP Semiconductors.

4

All other trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Copyright

© 2007–2011, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.