32-Channel 30mA Buck LED Driver with DOT

Each channel has individual 6-bit dot correction current adjustment and 12-bit gray scale PWM dimming. Combined with a 0.5μs minimum LED on-time, the LT3746 offers very wide dynamic contrast ratios. Both dot correction and gray scale dimming are accessible via a serial interface in TTL/CMOS logic. The LT3746’s 6V to 55V input voltage range makes it ideal for a wide range of input sources found in commercial and industrial designs, typically between 12V and 48V. The combination of minimal externals and a 5mm x 9mm QFN package provide a highly compact solution footprint for multichannel LED applications.

The LT3746’s internal buck controller generates an adaptive bus voltage slightly higher than the parallel LED strings to deliver efficiencies over 90%. 32 individual linear current sinks regulate and modulate individual LED strings, offering a wide range of functionality in a compact solution footprint. The LT3746 performs full diagnostics and protection against open/short LED and overtemperature faults, with the fault status sent via the serial data interface. The 30MHz fully buffered, skew-balanced, cascadable serial interface makes the LT3746 ideal for large screen LCD dynamic backlighting as well as full color LED displays.
The LT3746EUHH is available in a 56-lead 5mm x 9mm QFN package priced starting at $4.95 each, in 1,000-piece quantities. The extended temperature version the LT3746IUHH, or
I-grade, is also available, priced starting at $5.45 each in 1,000-piece quantities.

Summary of Features: LT3746
• 6V to 55V Power Input Voltage Range
• 32 Independent LED Outputs up to 30mA/13V
• 6-Bit Dot Correction Current Adjustment
• 12-Bit Gray Scale PWM Dimming
• 0.5μs Minimum LED On-Time
• Adaptive LED Bus Voltage for High Efficiency
• Cascadable 30MHz Serial Data Interface
• Full Diagnostics & Protection: Individual Open/Short LED & Overtemperature Fault
• 56-Lead 5mm x 9mm QFN Package
• 32-Channel 30mA Buck LED Driver