LT3744 - High Current Synchronous Step-Down LED Driver
- Ideal for Driving Up to 40A LEDs
- Up to 3000:1 PWM Dimming
- 20:1 Analog Dimming
- ±3% Current Regulation Accuracy
- ±3% Voltage Regulation Accuracy
- Unique Inverting Buck-Boost Topology Allows Grounded Heat Sink to Be Used for RGB LEDs
- 3.3V to 36V Input Voltage Range
- Peak Current Mode with DC LED Current Sensing
- Open and Shorted LED Protection and Fault Reporting
- Floating LED Driver Allows Single Power Solution to Drive Multicolor LEDs or Single LED with Three Different Regulated Currents
- Thermally Enhanced 5mm × 6mm QFN 36-Lead Package
The LT®3744 is a fixed frequency synchronous step-down DC/DC controller designed to drive a LED load at up to 20A continuous or 40A pulsed. The peak current mode controller will maintain ±3% LED current regulation over a wide output voltage range, from VEE to VIN. By allowing VEE to float to negative voltages, several LEDs in series can be driven from a single Li-Ion battery with a simple, single step-down output stage. PWM dimming is achieved with the PWM pins. The regulated LED current is set with analog voltages at the CTRL pins. Regulated voltage and overvoltage protection are set with a voltage divider from the output to the FB pin. The switching frequency is programmable from 100kHz to 1MHz through an external resistor on the RT pin.
Additional features include an accurate external reference voltage, a control input for thermally derating regulation current, an accurate EN/UVLO pin, an open-drain output fault flag, OVLO, frequency synchronization, and thermal shutdown.
CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.
For complete and up to date package information and drawings, please refer to our packaging page
- Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
- Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
- Please refer to our general ordering information or the product datasheet for more details
Package Variations and Pricing
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Demo BoardsLinear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.
|DC1930A||LT3744 Demo Board | Inverting Buck-Boost LED Driver, 3.3V ≤ VIN ≤ 30V, Drives 3 LEDs @ up to 12A||$249.00|
|DC2339A||LT3744 Demo Board | Sync Buck LED Driver, 5.5V ≤ VIN ≤ 24V, Drives 3 LEDs @ up to 20A Each||$175.00|
- LED Driver for DLP Projectors
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