16-Channel 50mA LED Driver with Buck Controller

The LT3745 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.

Applications

* Large Screen Display LED Backlighting

* Mono-, Multi-, Full-Color LED Displays

* LED Billboards and Signboards

* 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 6mm × 6mm QFN Package