100V, 100V LED Controller

The LT3756, LT3756-1 and LT3756-2 are DC/DC controllers designed to operate as a constant-current source for driving high current LEDs. They drive a low side external N-channel power MOSFET from an internal regulated 7.15V supply. The fixed frequency, current-mode architecture results in stable operation over a wide range of supply and output voltages. A ground referenced voltage FB pin serves as the input for several LED protection features, and also makes it possible for 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 or external component size.

The LT3756/LT3756-1/LT3756-2 sense output current at the high side of the LED string. High side current sensing is the most flexible scheme for driving LEDs, allowing boost, buck mode or buck-boost mode configuration. The PWM input provides LED dimming ratios of up to 3000:1, and the CTRL input provides additional analog dimming capability.

Applications

* High Power LED Applications

* Current Limited Constant Voltage Applications

* Battery Charging

* 3000:1 True Color PWM™ Dimming

* Wide Input Voltage Range: 6V to 100V

* Output Voltage Up to 100V

* Constant-Current and Constant-Voltage Regulation

* 100mV High Side Current Sense

* Drives LEDs in Boost, Buck Mode, Buck-Boost Mode, SEPIC or Flyback Topology

* Adjustable Frequency: 100kHz to 1MHz

* Open LED Protection

* Programmable Undervoltage Lockout with Hysteresis