Advanced Analog Technology, Inc.
May 2008
AAT1168/1168A/1168B
Product information presented is current as of publication date. Details are subject to change without notice.
TRIPLE-CHANNEL TFT LCD POWER SOLUTION
WITH OPERATIONAL AMPLIFIERS
FEATURES
Built in 3A, 0.2
Switching NMOS
Positive LDO Driver Up to 28V/5mA
Negative LDO Driver Down to
−
14V/5mA
1
V
COM
and 4
V
GAMMA
Operational Amplifiers
28V High Voltage Switch for VGH
Internal Soft-Start Function
1.2MHz Fixed Switching Frequency
3 Channels Fault and Thermal Protection
Low Dissipation Current
QFN-32 Package Available
GENERAL DESCRIPTION
The AAT1168/AAT1168A/AAT1168B is a triple-channel
TFT LCD power solution that provides a step-up PWM
controller, two LDO drivers (one for positive high voltage
and one for negative voltage), five operational amplifiers,
and one high voltage switch up to 28V for TFT LCD
display.
The PWM controller consists of an on-chip voltage
reference, oscillator, error amplifier, current sense circuit,
comparator,
under-voltage
lockout
protection
and
internal soft-start circuit. The thermal and power fault
protection prevents internal circuit being damaged by
excessive power.
The LDO drivers generate two regulated output voltage
set by external resistor dividers. VGH voltage does not
activate until DLY voltage exceeds 1.25V.
The
AAT1168/AAT1168A/AAT1168B
contains
4+1
operational amplifiers. VO1, VO2, VO4, and VO5 are for
PIN CONFIGURATION
VOUT3
1
VREF
2
24
EO
23
IN1
gamma corrections and VO3 is for
V
COM
. In the short
circuit condition, operational amplifiers are capable of
sourcing
±
100mA
current for
V
GAMMA
, and
±
200mA
current for
V
COM
.
With
the
minimal
external
components,
the
AAT1168/A/B offers a simple and economical solution
GND
3
GND1
VO1
VI1-
VI1+
VO2
4
5
6
7
8
AAT1168/
AAT1168A/
AAT1168B
22
VDD
21
SW
20
VO5
19
VI5-
18
for TFT LCD power.
VI5+
17
VO4
–
–
Advanced Analog Technology, Inc. –
Version 1.00
Page 1 of 22
司公限有�½股技科比類灣台
–