LT3474 Datasheet PDF

●The LT3474EFE#PBF is a Step-down 1A LED Driver 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. 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 regulates a broad array of power sources, from 5V logic rails to unregulated wall transformers, lead acid batteries and distributed power supplies. A current mode PWM architecture provides fast transient response and cycle-by-cycle current limiting. Frequency fold back and thermal shutdown provide additional protection.

● True colour PWM™ delivers constant colour with 400:1 dimming range

● Up to 1A LED current

● Adjustable 200kHz to 2MHz switching frequency

● Adjustable control of LED current

● Integrated boost diode

● High output current accuracy is maintained over a wide range from 35mA to 1A

● Open LED and short-circuit protection

● High side sense allows grounded cathode connection

● Uses small inductors and ceramic capacitors