Only For Training And Service Purposes - LG KG270 Service Manual

Signals
CS3
SSC0_MTSR
SSC0_CLK
LCD_RESET
MLED
MLED1/2
2V8_VIO
The AAT3157 is a low noise, constant frequency charge pump DC/DC converter that uses a trimode
load switch (1X), fractional (1.5X), and doubling (2X) conversion to maximize efficiency for white LED
applications. The AAT3157 is capable of driving up to three channels of LEDs at 20mA per channel
from a 2.7V to 5.5V input.
The current sinks may be operated individually or in parallel for driving higher current LEDs. A low
external parts count (two 1µF flying capacitors and two small 1µF capacitors at VIN and VOUT) make
this part ideally suited for small, battery-powered applications. AnalogicTech's S2Cwire™ (Simple
Serial Control™) serial digital input is used to enable, disable, and set current for each LED with 16
settings down to 50µA.
The low-current mode supply current can be as low as 50µA to save power.
Data
1
2
3
4
5
6
7
8
Copyright © 2007 LG Electronics. Inc. All right reserved.

Only for training and service purposes

This signal enable to access to the driver IC of LCD.
This signal transfer serial data to driver IC.
This signal transfer serial clock to driver IC.
This signal makes driver IC to HW default status.
This signal provide power to white LEDs.
This signal be feed back from white LEDs.
This signal provides power to LCD modules.(2.8V)
Output (mA/Ch)
20.0
17.0
14.0
12.0
10.0
8.6
7.0
6.0
Figure 3-5-3. Charge pump Output Current
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3. TECHNICAL BRIEF
Description
Data Output (mA/Ch)
9
10
11
12
13
14
15
16
5.0
4.2
3.4
2.8
1.0
0.5
0.1
0.05
LGE Internal Use Only