LT3474

• Product introduction

LT3474 step-down 1A LED driver

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description

LT^®The 3474/LT3474-1 are fixed frequency step-down DC/DC converters designed for use as a constant current source. An internal sense resistor monitors the output current for accurate current regulation, making it ideal for driving high current LEDs. The high output current accuracy is maintained over a wide range (35mA to 1A), providing a wide dimming range.

The unique PWM circuit achieves a dimming range of 400:1, thus avoiding the color drift common in LED current dimming operation.

The high switching frequency offers many advantages and allows the use of small inductors and ceramic capacitors. The combination of a small inductor and a 16-pin TSSOP surface-mount package results in a lower footprint and lower cost than alternative solutions. The combination of constant switching frequency and low impedance ceramic capacitors results in lowandPredictable output ripple.

With its wide input range of 4V to 36V, the LT3474/LT3474-1 regulate a wide range of supplies, from 5V logic rails to unregulated wall transformers, lead-acid batteries and distributed power. The current-mode PWM architecture provides fast transient response and cycle-by-cycle current limit. Frequency foldback and thermal shutdown provide additional protection.

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• Automotive and aviation lighting
• Local lighting of buildings
• Illumination on the back of the monitor
• Constant current source