Linear Technology LT3746 buck LED driver

Linear Technology has announced the LT3746, a 32-channel LED driver integrated with a 55 V step-down controller. The driver powers up to 30 mA of LED current for each channel, which can drive up to 13 LEDs in series, making it suitable for applications such as large LED billboards.

Each channel has individual 6-bit dot correction current adjustment and 12-bit greyscale PWM dimming. Combined with a 0.5 µs minimum LED on-time, the device offers wide dynamic contrast ratios.

Both dot correction and greyscale dimming are accessible via a serial interface in TTL/CMOS logic. The LT3746’s 6 to 55 V input voltage range makes it suitable for a wide range of input sources found in commercial and industrial designs.

The internal buck controller generates an adaptive bus voltage slightly higher than the parallel LED strings to deliver efficiencies over 90%. Thirty-two individual linear current sinks regulate and modulate individual LED strings, offering a wide range of functionality in a compact solution footprint.

The driver performs full diagnostics and protection against open/short LED and overtemperature faults, with the fault status sent via the serial data interface.

The 30 MHz fully buffered, skew-balanced, cascadable serial interface makes it suitable for large screen LCD dynamic backlighting as well as full colour LED displays.