Power Electronics

Step-down DC-DC Converter

THE LT3743 synchronous step-down dc-dc converter from Linear Technology delivers up to 20 A constant current from a nominal 12-V input, delivering in excess of 80 W to drive high-current LEDs. An input voltage range of 5.5 to 36 V suits applications such as industrial, DLP projection, and architectural lighting.

In pulsed LED applications, the dc-dc converter can deliver up to 40 A (160 W) from a 12-V input. Efficiencies as high as 95% eliminate any need for external heat sinking and significantly simplify thermal design.

A frequency-adjust pin enables the user to program frequency between 100 kHz and 1 MHz so designers can optimize efficiency and minimize external component size. Available in a 4- × 5-mm, 28-pin QFN (LT3743EUFD) or a thermally enhanced TSSOP-28 package (LT3743EFE), the device offers both PWM and CTRL_SELECT dimming, with 3,000:1 dimming capabilities at three current levels to suit color-mixing.

Similarly, the device's unique topology enables it to transition between two regulated LED current levels in less than 2 µs. LED current accuracy of ±6% is maintained to ensure the most accurate luminosity of light from the LED.

Pricing starts at $4.80 (LT3743EUFD) and $4.95 (LT3743EFE) each in 1,000-piece quantities. All versions are available from stock.
Linear Technology
Milipitas, CA


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