摘要：  austriamicrosystems公司的AS3693B 是16路高精度LED控制器，内置的PWM发生器用来驱动LCD屏背景光的外接FET.外接时钟和同步输入允许LCD背景光和TV图像同步.输出电压检测高达50V，电流绝对值的精度在±0.5%，内置了5V旁路稳压器.所有的电路参数可通过I2C或SPI接口编程.本文介绍了AS3693B的主要特性和应用示意图.

关键字：  LED控制器，  LCD屏，  稳压器

austriamicrosystems公司的AS3693B 是16路高精度LED控制器，内置的PWM发生器用来驱动LCD屏背景光的外接FET.外接时钟和同步输入允许LCD背景光和TV图像同步.输出电压检测高达50V，电流绝对值的精度在±0.5%，内置了5V旁路稳压器.所有的电路参数可通过I2C或SPI接口编程.本文介绍了AS3693B的主要特性和应用示意图.

16 channel high precision LED controller for LCD backlight

The AS3693B is a 16 cannels high precision LED controller with build in PWM generators for driving external FETs in LCD-backlight panels.

External clock and synchronizing inputs allow the synchronization of the LCD backlight with the TV picture. Local dimming and scan dimming is supported by 16 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.

AS3693B主要特性:

16 independent LED channels

External FET control and current sensing

Output voltage sense up to 50V

Absolute current accuracy ±0.5%

Output slew rate limited to reduce EMI

Current programmable with external resistor

16 independent PWM generators with 12 bit resolution

H-Sync， V-Sync inputs to synchronize with TVset

Three independent power feedback for R-， G-， B-supply regulation

Build in 5V shunt regulator

I2C or SPI interface with 5 bit device address

Fault interrupt output

Open LED detection

Short LED detection

Temperature shutdown

Package epTQFP64

应用:

LED Backlighting for LCD – TV Sets and Monitors

图1. AS3693B方框图和应用示意图