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 LT3745 offers very wide dynamic contrast ratios. Both dot correction and gray scale dimming are accessible via a serial interface in TTL/CMOS logic. The LT3745’s 6V to 55V input voltage range is well suited 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 6mm x 6mm QFN package provide a highly compact solution footprint for multichannel LED applications.
The LT3745’s internal buck controller generates an adaptive bus voltage slightly higher than the parallel LED strings to deliver efficiencies over 90%. Sixteen individual linear current sinks regulate and modulate individual LED strings, offering a wide range of functionality in a compact solution footprint. The LT3745 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 LT3745 ideal for large screen LCD dynamic backlighting as well as full color LED displays.
The LT3745EUJ is available in a 40-lead 6mm x 6mm QFN package, priced starting at $4.95 each, in 1,000-piece quantities. The extended temperature version the LT3745IUJ, or I-grade, is also available, priced starting at $5.45 each in 1,000-piece quantities. All versions are available from stock.
Summary of Features: LT3745
• 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 & Protection: Individual Open/Short LED & Overtemperature Fault
• 40-Lead 6mm x 6mm QFN Package
• 16-Channel 50mA Buck LED Driver