Linear LT3746 32路20mA LED驅動解決方案

Linear 公司的LT3746 是32路20mA LED驅動器，集成了55V降壓控制器，每路可驅動30mA/13V串聯led，6位點修正電流調整和12位灰度級PWM調光。器件工作電壓6V-55V，主要用在大型顯示屏LED背光，單色，多色和全色LED顯示以及LED標牌。本文介紹了LT3746主要特性，方框圖以及多種應變用電路。

LT3746：32-ChannEL 20mA LED Driver with Buck Controller

The LT3746 integrates a 32-channel LED driver with a 55V buck controller. The LED driver lights up to 30mA/13V of LEDs in series per channel, and the buck controller generates an adaptive bus voltage supplying the parallel LED strings. Each channel has individual 6-bit dot correction current adjustment and 12-bit grayscale PWM dimming. Both dot correction and grayscale are accessible via a serial data interface in TTL/CMOS logic.

The LT3746 performs full diagnostic and protection against open/short LED and overtemperature fault. The fault status is sent back through the serial data interface.
The 30MHz fully-buffered, skew-balanced, cascadable serial data interface makes the chip extremely suitable for large screen LCD dynamic backlighting and mono-,multi-, full-color LED displays.

LT3746主要特性:

6V to 55V Power Input Voltage Range

32 Independent LED Outputs up to 30mA/13V

6-Bit Dot Correction Current Adjustment

12-Bit Grayscale PWM Dimming

0.5μs Minimum LED On Time

Adaptive LED Bus Voltage for High Efficiency

Cascadable 30MHz Serial Data Interface

Full Diagnostic and Protection: Individual Open/Short LED and Overtemperature Fault

LT3746應用:

Large Screen Display LED Backlighting

Mono-, Multi-, Full-Color LED Displays

LED Billboards and Signboards

圖1。LT3746方框圖

圖2。LT3746典型應用電路（1）

圖3。LT3746典型應用電路（2）：32路LED驅動器，每路10-30mA，100Hz 12位調光

圖4。LT3746典型應用電路（3）：32路LED驅動器，每路10-30mA，500Hz 12位調光