Document
BUF22821
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
FEATURES
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•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
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 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.
16x Nonvolatile Memory BANK0 16x Nonvolatile Memory BANK1
¼
DAC Registers
¼
DAC Registers
¼ ¼ ¼
OUT2
OUT21
OUT22 STATINL
STATOUTL
AVDD
VCOM1
RELATED PRODUCTS
FEATURES 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
PRODUCT BUF12800 BUF20800 BUF20820 BUF01900 BUF11704 BUF11705
SDA SCL
Control IF A0
VCOM2 BUF22821
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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.
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I2C is a trademark of NXP Semiconductors.
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All other trademarks are the property of their respective owners.
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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
BUF22821
SBOS399D – JUNE 2007 – REVISED JULY 2011
www.ti.com
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications.
PRODUCT BUF22821
PACKAGE/ORDERING INFORMATION(1)
PACKAGE
PACKAGE DESIGNATOR
HTSSOP-38
DCP
PACKAGE MARKING BUF22821
(1) For the most current package and ordering information see the Package Option Addendum at the end of this document, or see the TI web site at www.ti.com.
ABSOLUTE MAXIMUM RATINGS(1)
Over operating free-air temperature range (unless otherwise noted).
Supply Voltage, VS Supply Voltage, VSD Digital Input Terminals, SCL, SDA, AO, BKSEL: Voltage Digital Input Terminals, SCL, SDA, AO, BKSEL: Current Analog Input Terminals, STATINL, STATINH: Voltage Analog Input Terminals, STATINL, STATINH: Current Output Short-Circuit(2) Operating Temperature Storage Temperature Junction Temperature
Human Body Model ESD Ratings Charged-Device Model
Machine Model
BUF22821 +22 +6
–0.5 to +6 ±10
–0.5 to VS + 0.5 ±10
Continuous –40 to +95 –65 to +150
+125 4000 1000 200
UNIT V V V mA V mA
°C °C °C V V V
(1) Stresses above these ratings may cause permanent damage. Exposure to absolute maximum conditions for extended periods may degrade device reliability. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those specified is not implied.
(2) Short-circuit to ground, one channel at a time.
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Copyright © 2007–2011, Texas Instruments Incorporated
BUF22821
www.ti.com
SBOS399D – JUNE 2007 – REVISED JULY 2011
ELECTRIC.