60V Synchronous Boost LED Controller

The LT3762 is a synchronous DC/DC controller designed to operate as a constant-current source and constant-voltage regulator. It features a programmable internal PWM dimming signal generator and a synchronous gate driver. The LT3762 is ideally suited for driving high current LEDs with high efficiency and reduced power loss. Rail-to-rail switch current sensing enables synchronous boost topologies and nonsynchronous topologies such as SEPIC. A voltage feedback pin serves as the input for several LED protection features and also allows the converter to operate as a constant-voltage source.

A frequency adjust pin allows the user to program the frequency from 100kHz to 1MHz to optimize efficiency, performance and external component size. Adding a capacitor at SSFM pin activates the Spread-Spectrum Modulation feature to reduce EMI. The LT3762 also includes an integrated DC/DC converter to efficiently produce a regulated 7.5V supply for the N-channel MOSFET gate drivers. The PWM pin controls PWMTG to drive the P-channel MOSFET, allowing a high PWM dimming range (3000:1) and providing LED overcurrent protection and short-circuit protected boost capability.

Applications

* Industrial and Automotive Lighting

* Accurate Current-Limited Voltage Regulators

* 3000:1 External PWM Dimming

* 250:1 Internal PWM Dimming

* Wide VIN Operating Range: 2.5V to 38.5V

* Synchronous Boost Output Voltage up to 60V

* Spread-Spectrum Frequency Modulation for Lower EMI

* PMOS Switch Driver for PWM and Output Disconnect

* Constant Current (±3.5%) Regulation

* Constant Voltage (±2%) Regulation