LT3474IFE#PBF

The LT3474IFE#PBF is a fixed frequency step-down DC/DC Converter designed to operate as constant-current sources. An internal sense resistor monitors the output current allowing accurate current regulation, ideal for driving high current LEDs. High output current accuracy is maintained over a wide current range, from 35mA to 1A, allowing a wide dimming range. Unique PWM circuitry allows a dimming range of 400:1, avoiding the colour shift normally associated with LED current dimming. The high switching frequency offers several advantages, permitting the use of small inductors and ceramic capacitors. The constant switching frequency combined with low-impedance ceramic capacitors result in low, predictable output ripple. With its wide input range of 4 to 36V, the LT3474 regulate a broad array of power sources, from 5V logic rails to unregulated wall transformers, lead acid batteries and distributed power supplies. Frequency fold-back and thermal shutdown provide additional protection.