BUF08800 Datasheet, PDF (6/23 Pages) Burr-Brown (TI) – Programmable Reference Generator and 400mA VCOM Driver

BUF08800
SBOS380A − FEBRUARY 2007 − REVISED MAY 2007
APPLICATIONS INFORMATION
The BUF08800 programmable voltage reference allows
fast and easy adjustment of eight programmable reference
outputs, each with 10-bit resolution. It allows very simple,
time-efficient adjustment of the V_COM and gamma
reference voltages. The BUF08800 is programmed
through a high-speed, standard two-wire interface. The
BUF08800 features a double-register structure for each
digital-to-analog converter (DAC) channel to simplify the
implementation of dynamic gamma control (see the
Dynamic Control section). This architecture allows
pre-loading of register data and rapid updating of all
channels simultaneously.
V_COM (OUT 1) and buffers 2−4 are able to swing to within
200mV of the positive supply rail, and to within 1V of the
negative supply rail. Buffers 5−8 are able to swing to within
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1V of the positive supply rail, and to within 250mV of the
negative supply rail. (See the Electrical Characteristics
table for further information.)
Buffers 2−8 are capable of full-scale change in output
voltage in less than 4µs; see Figure 4.
The BUF08800 uses an analog supply of 7V to 22V and a
digital supply of 2V to 5.5V. The digital supply must be
applied prior to or simultaneously with the analog supply
to avoid excessive current and power consumption;
damage to the device may occur if it is left connected only
to the analog supply for an extended time.
Figure 10 shows the BUF08800 in a typical configuration.
In this configuration, the BUF08800 device address is 74h.
The output of each DAC is immediately updated as soon
as data is received in the corresponding register (LD = 0).
3.3V
1µ F
100nF
Timing
Controller
BUF08800
(1)
1 GND
V_COM (O UT 1) 20
(1)
V_COM
2 GND
3 +IN (V_COM)
4 ^−IN (V_COM)
5 VSD
6 SCL
V_S 19
V_S 18
OUT 2 17
OUT 3 16
OUT 4 15
7 SDA
OUT 5 14
8 A0
OUT 6 13
9 LD
OUT 7 12
10 GND (digital)⁽²⁾
OUT 8 11
10µF
V_S
100µF
(1)
(1)
Source
Driver
(1)
(1)
(1)
(1)
(1)
(1) _{RC combination optional}
(2) _{GND and GND (digital) are internally connected and must be at the same voltage potential.}
Figure 10. Typical Application Configuration
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