Linear Technology pushes 32-channel LED driver LT3746

Photocoupler

Linear Technology Corporation has introduced the LT3746, a 32-channel LED driver that integrates a 55V buck controller. This device is capable of delivering up to 30mA of current per channel and can power series LEDs up to 13V, making it well-suited for large-scale applications such as LED billboards and signage. Each channel features a 6-bit current correction and 12-bit grayscale PWM dimming, allowing precise control over brightness and color accuracy. With a minimum LED on-time of just 0.5μs, the LT3746 supports an impressive dynamic contrast ratio, enhancing visual quality in high-end displays.

The LT3746 offers a flexible serial interface (TTL/CMOS logic) for both point correction and grayscale dimming, simplifying system integration. Its wide input voltage range—6V to 55V—makes it ideal for commercial and industrial systems that typically operate between 12V and 48V. The device's compact 5mm x 9mm QFN package, combined with minimal external components, ensures a space-efficient solution for multi-channel LED designs.

Inside, the LT3746 uses an internal step-down controller to generate an adaptive bus voltage slightly above the parallel LED string, achieving efficiency of over 90%. It also employs 32 linear current sinks to regulate and modulate individual LED strings, enabling advanced lighting features without compromising performance. Comprehensive diagnostics and protection mechanisms are built-in, including detection for LED open/short circuits and overtemperature faults, with fault status reported through the serial data interface.

The LT3746’s 30MHz full-buffered, slew-rate balanced, and cascadable serial interface makes it an excellent choice for dynamic backlighting in large-screen LCDs and full-color LED displays. The LT3746EUHH is available in a 56-lead QFN package at $4.95 per unit for 1,000-piece orders, while the extended temperature grade version, LT3746IUHH, is priced at $5.45 each for the same quantity. All versions are in stock and ready for immediate shipment. For more details, visit the official website.