BUF22821 Datasheet, PDF (1/25 Pages) Texas Instruments – Programmable Gamma-Voltage Generator and VCOM Calibrator with Integrated Two-Bank Memory

BurrĆBrown Products
from Texas Instruments
BUF22821 ®
BUF22821
SBOS399 – JUNE 2007
Programmable Gamma-Voltage Generator and
V_COM Calibrator with Integrated Two-Bank Memory
FEATURES
• 24-CHANNEL GAMMA
– 22-CHANNEL PROGRAMMABLE
– 2-CHANNEL STATIC GAMMA
• 2-CHANNEL PROGRAMMABLE V_COM
• 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
BKSEL
Digital
Analog
(2.0V to 5.5V) (9V to 20V)
1
STATOUTH
STATINH
AVDD
OUT1
DESCRIPTION
The BUF22821 offers 22 programmable gamma
channels, two programmable V_COM 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 V_COM 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 V_COM 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.
OUT2
OUT21
OUT22
STATINL
STATOUTL
AVDD
V_COM1
RELATED PRODUCTS
FEATURES
12-Channel Gamma Correction Buffer
20-Channel Programmable Buffer, 10-Bit, V_COM
16-/20-Channel Programmable Buffer with Memory
Programmable V_COM Driver
18V Supply, Traditional Gamma Buffers
22V Supply, Traditional Gamma Buffers
PRODUCT
BUF12800
BUF20800
BUF20820
BUF01900
BUF11704
BUF11705
V_COM2
SDA
SCL
Control IF
A0
BUF22821
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, Texas Instruments Incorporated