LT3474EFE#TRPBF

The LT®3474 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. Unique PWM circuitry allows a dimming range of 400:1, avoiding the color 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. A current mode PWM architecture provides fast transient response and cycle-by-cycle current limiting. Frequency foldback and thermal shutdown provide additional protection. Typical applications are automotive and avionic lighting, architectural detail lighting, display backlighting, constant current sources.

• True color PWM™ delivers constant color with 400:1 dimming range
• Up to 1A LED current, integrated boost diode
• Adjustable control of LED current
• High side sense allows grounded cathode connection
• Uses small inductors and ceramic capacitors
• Minimum input voltage is 3.5V typical (TA=25°C. VIN=12V, VBOOST=16V, VOUT=4V)
• Input quiescent current 2.6mA typ (TA=25°C. VIN=12V, VBOOST=16V, VOUT=4V)
• Switching frequency range from 470 to 530KHz (RT=80.6k)
• 16-lead TSSOP package
• Temperature rating range from –40°C to 85°C

Notes

ADI products are only authorized (and sold) for use by the customer and are not to be resold or otherwise passed on to any third party