Linear Technology's LT3743 synchronous step-down DC/DC converter delivers constant current to drive high current LEDs. The device's 5.5V to 36V input voltage range makes it ideal for a wide variety of applications, including industrial, DLP projection and architectural lighting. The LT3743 provides up to 20A of continuous LED current from a nominal 12V input, delivering in excess of 80W. In pulsed LED applications, it can deliver up to 40A of LED current or 160W from a 12V input. Efficiencies as high as 95% eliminate any need for external heat sinking and significantly simplify the thermal design. A frequency adjust pin enables the user to program the frequency between 100kHz and 1MHz so designers can optimize efficiency while minimizing external component size. Combined with a 4x5mm QFN or thermally enhanced TSSOP-28 package, the LT3743 offers a very compact high-power LED driver solution.
The LT3743 offers both PWM and CTRL_SELECT dimming, offering 3,000:1 dimming capability at three LED current levels, making it ideal for color mixing applications such as those required in DLP projectors. Similarly, the LT3743's unique topology enables it to transition between two regulated LED current levels in less than 2µs, enabling more accurate color mixing in RGB applications. LED current accuracy of ±6 percent is maintained in order to ensure the most accurate luminosity of light from the LED. Additional features include output voltage regulation, open-LED protection, overcurrent protection and a thermal derating circuit.
The LT3743EUFD is available in a 28-pin 4x5mm QFN package, whereas the LT3743EFE is available in a thermally enhanced TSSOP-28.
Linear Technology LT3743 Step-Down LED Driver
Linear Technology
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