Linear 公司的LT3746 是32路20mA LED驱动器，集成了55V降压控制器，每路可驱动30mA/13V串联LED，6位点修正电流调整和12位灰度级PWM调光。器件工作电压6V-55V，主要用在大型显示屏LED背光，单色，多色和全色LED显示以及LED标牌。本文介绍了LT3746主要特性，方框图以及多种应变用电路。

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应用:

Large Screen Display LED Backlighting

Mono-, Multi-, Full-Color LED Displays

LED Billboards and Signboards

图1。LT3746方框图

图2。LT3746典型应用电路（1）

图3。LT3746典型应用电路（2）：32路LED驱动器，每路10-30mA，100Hz 12位调光

图4。LT3746典型应用电路（3）：32路LED驱动器，每路10-30mA，500Hz 12位调光
详情请见：
http://cds.linear.com/docs/Datasheet/3746f.pdf