BUF20820 Datasheet, PDF (1/32 Pages) Burr-Brown (TI) – 18-Channel GAMMA VOLTAGE GENERATOR with Two Programmable VCOM Channels

BUF20820
SBOS330C − DECEMBER 2005 − REVISED OCTOBER 2006
18-Channel GAMMA VOLTAGE GENERATOR
with Two Programmable V_COM Channels
FEATURES
D 18-CHANNEL GAMMA CORRECTION
D 2-CHANNEL PROGRAMMABLE V_COM:
100mA I_OUT
D ON-CHIP OTP MEMORY
D 10-BIT RESOLUTION
D RAIL-TO-RAIL OUTPUT
D LOW SUPPLY CURRENT: 900µA/ch
D SUPPLY VOLTAGE: 7V to 18V
D DIGITAL SUPPLY: 2.0V to 5.5V
D INDUSTRY-STANDARD, TWO-WIRE
INTERFACE: 3.4MHz HIGH-SPEED MODE
D HIGH ESD RATING:
4kV HBM, 1kV CDM, 200V MM
D DEMO BOARD AND SOFTWARE AVAILABLE
2V−5.5V
Digital
BUF20820
7V−18V
Analog
REFH
SDA
SCL
Control IF
LD
AO
REFH OUT
OUT 1
OUT 2
18 Output Channels plus
Two V_COM Channels
OUT 17
OUT 18
V_{COM OUT1}
V_{COM OUT2}
REFL OUT
REFL
APPLICATIONS
D REPLACES RESISTOR-BASED GAMMA
SOLUTIONS
D TFT-LCD REFERENCE DRIVERS
D DYNAMIC GAMMA CONTROL
DESCRIPTION
The BUF20820 is a programmable voltage reference
generator designed for gamma correction in TFT-LCD
panels. It provides 18 programmable outputs for gamma
correction and two channels for V_COM adjustment, each
with 10-bit resolution. It offers on-chip One-Time
Programmable (OTP) memory that allows the user to store
the gamma voltages on-chip. This eliminates the need for
an external EEPROM.
This programmability replaces the traditional, time-
consuming process of changing resistor values to optimize
the various gamma voltages and allows designers to
determine the correct gamma voltages for a panel very
quickly. Required voltage changes can also be easily
implemented without hardware changes.
The BUF20820 uses TI’s latest, small-geometry analog
CMOS process, which makes it a very competitive choice
for full production, not just evaluation.
Programming of each output occurs through an industry-
standard, two-wire serial interface. Unlike existing
programmable buffers, the BUF20820 offers a high-speed
mode that allows clock speeds up to 3.4MHz.
For lower or higher channel count, please contact your
local sales or marketing representative.
The BUF20820 is available in an HTSSOP-38
PowerPAD package. It is specified from −40°C to +85°C.
BUF20820 RELATED PRODUCTS
FEATURES
18-Channel Programmable, Two V_COM
12-Channel Programmable Buffer, 10-Bit
Programmable V_COM with Memory
10-Channel Gamma Correction Buffer, Int V_COM,
18V Operating Supply Voltage
High-Speed V_COM, 1 and 2 Channels
Complete LCD DC/DC Solution
PRODUCT
BUF20800
BUF12800
BUF01900
BUF11704
SN10501
TPS651xx
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semiconductor products and disclaimers thereto appears at the end of this data sheet.
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PRODUCTION DATA information is current as of publication date. Products
conform to specifications per the terms of Texas Instruments standard warranty.
Production processing does not necessarily include testing of all parameters.
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