AS3694 Datasheet, PDF (1/3 Pages) ams AG – 12 channel high precision LED driver for LCD backlight and 3 DCDC Step Up controller

AS3694
Product Brief
AS3694
12 channel high precision LED driver for LCD backlight and
3 DCDC Step Up controller
Product Brief
1 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.
2 Key Features
ƒ 12 independent LED channels
ƒ Output current 70mA
ƒ Output voltage up to 50V
ƒ Absolute current accuracy ±0.5%
ƒ Output slew rate limited to reduce EMI
ƒ Current programmable with external resistor
ƒ 12 independent PWM generators with 12 bit
resolution
ƒ H-Sync, F-Sync inputs to synchronize with TV-
set
ƒ Three independent power feedback for R-, G-,
B-supply regulation
ƒ Build in 5V shunt regulator
ƒ I2C or SPI interface with 6 bit address
ƒ Fault interrupt output
ƒ Open LED detection
ƒ Short LED detection
ƒ Temperature shutdown
ƒ 3 DCDC Step Up controller
ƒ Current mode
ƒ Efficiency > 90%
ƒ Input voltage range 15V to 50V
ƒ Output voltage up to 50V / 200mA
ƒ Package epTQFP64
3 Application
LED Backlighting for LCD – TV Sets and Monitors
www.austriamicrosystems.com (mpa)
Revision 1.1 / 2007-11-25
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