Features and Benefits
- 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
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.
- Large Screen Display LED Backlighting
- Mono-, Multi-, Full-Color LED Displays
- LED Billboards and Signboards
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (1)
Demonstration circuit 1608A features the LT3745, a 16-channel 50mA buck LED driver controller and serial interface. Each channel drives a single LED. Three LT3745's are connected in series with each one controlling a color in a 16 LED RGD array. Each channel has an individually adjustable 12-bit (4096-step) grayscale PWM dimming control and a 6-bit (64-step) dot correction current adjustment.
The demo board input voltage range is 9V to 40V and the buck controller outputs 3.4V or 4.2V depending on the color of the LED.
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
Models for the following parts are available in LTspice:
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.