AS3694

Product Brief

www.austriamicrosystems.com (mpa)

Revision 1.1 / 2007-11-25

1 - 3

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General Description

The AS3694 is a 12 cannels high precision LED

driver with build in PWM generators for building

backlight panels in LCD-TV-sets. 3 DCDC Step Up

controllers can be used to build the power supplies

for red, green and blue LED strings.

External clock and synchronizing inputs allow the

synchronization of the LCD backlight with the TV

picture. Local dimming and scan dimming is

supported by 12 independent PWM generators with

programmable delay, period and duty cycle. Three

free configurable dynamic power feedback circuits

make the device usable for white LED as well as

RGB backlights. Build in safety features include

thermal shutdown as well as open and short LED

detection. All circuit parameters are programmable

via I2C or SPI interface.

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Key Features

12 independent LED channels

Output current 70mA

Output voltage up to 50V

Absolute current accuracy ±0.5%

Output slew rate limited to reduce EMI

Current programmable with external resistor

12 independent PWM generators with 12 bit

resolution

H-Sync, F-Sync inputs to synchronize with TV-

set

Three independent power feedback for R-, G-,

B-supply regulation

Build in 5V shunt regulator

I2C or SPI interface with 6 bit address

Fault interrupt output

Open LED detection

Short LED detection

Temperature shutdown

3 DCDC Step Up controller

Current mode

Efficiency > 90%

Input voltage range 15V to 50V

Output voltage up to 50V / 200mA

Package epTQFP64

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Application

LED Backlighting for LCD – TV Sets and Monitors

AS3694

12 channel high precision LED driver for LCD backlight and

3 DCDC Step Up controller

Product Brief