at1736 Aimtron Technology, at1736 Datasheet - Page 12

• Manufacturer Part Number: at1736
• Description: Lcd Panel Power Supplies With High-current Operational Amplifiers
• Manufacturer: Aimtron Technology

AT1736
Preliminary Product Information
LCD Panel Power Supplies with
High-Current Operational Amplifiers
Function Description
The AT1736 consists of a high-performance step-up converter, two linear regulator
controllers, five high-current operational amplifiers, and a gate-on pulse modulator.
The step-up DC-DC converter generates the source-driver supply voltage. The two
linear regulator controllers provide the regulated positive gate-on and negative
gate-off supply voltages from external charge pumps. The operational amplifiers
supply the VCOM and GAMMA buffers with high output current, fast slew rate and
wide bandwidth performances for driving capacitive loads. The gate-on pulse
modulator controls the positive gate-on voltage waveform for reducing the flicker on
TFT LCD panel.
Step-up Converter
The step-up DC-DC converter adopts the PWM current mode control, fixed 1.2MHz
switching frequency and an internal 2.4A, 0.16Ω (typical) power MOSFET. Such
architecture provides faster line and load transient response for the specific
performance of the source-driver supply voltage source. The high switching frequency
can minimize the components as the space of thick LCD panel required. The internal
soft-start function uses 8 steps digital current limit to restrain the inrush current and
output voltage overshoot and also to reduce the pin number of the chip and the
external component. The external compensation network provides the flexibility in
determining output voltage regulation accuracy and dynamic response.
Figure 1. Step-up converter block diagram
7F, No.9,PARK AVENUE. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
http://www.aimtron.com.tw
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10/19/2007 REV:0.5
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