Linear公司的LT3745是帶55V降壓控制器的16路50mA LED驅動器,每路可點亮75mA/36V 串聯LED,而降壓控制器產生合適的總線電壓給并聯LED串供電.每路有6位點陣電流修正,12位灰度PWM調光.LED電流匹配在+/-3%內.主要用在大屏幕顯示器LED背光,單色/多色/全色LED顯示器以及LED信號板.本文介紹了LT3745 主要特性,方框圖以及典型應用電路.

LT3745:16-Channel 50mA LED Driver with Buck Controller

The LT.3745 integrates a 16-channel LED driver with a 55V buck controller. The LED driver lights up to 75mA/36V 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. A +/-3% LED current matching and a 0.5μs minimum LED on-time can be achieved at 50mA per channel.

The LT3745 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.

LT3745 主要特性:

6V to 55V Power Input Voltage Range

16 Independent LED Outputs Up to 75mA/36V

±3% LED Current Matching at 50mA (Typ ±1%)

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

40-Lead 6mmx6mm QFN Package

LT3745應用:

Large Screen Display LED Backlighting

Mono-, Multi-, Full-Color LED Displays

LED Billboards and Signboards

圖1. LT3745方框圖

圖2. LT3745 16路LED驅動器: 500kHz降壓,每路LED電流25mA 到75mA,100Hz 12位調光


圖3. LT3745 16路LED驅動器: 1MHz降壓,每路10個LED,電流25mA 到75mA,500Hz 12位調光
詳情請見:
http://cds.linear.com/docs/Datasheet/3745f.pdf