DC1160A: 330mA @ 40V Max, 3 ~ 40V in

Demonstration circuit 1160 is a full-featured LED driver with 2.3A switch current featuring the LT®3518. The board is optimized to drive a 330mA LED string with a total LED voltage between the input voltage and 40V in a boost topology. The high input voltage range, high efficiency low side internal 2.3A NPN power switch, low voltage floating current sense amplifier, soft-start, high side PMOS PWM gate driver, high PWM dimming ratio, overvoltage protection, shutdown control pin, analog LED current dimming control, and externally programmable switching frequency (with sync) make the LT3518 an extremely versatile and powerful LED driving IC.

The LT3518 has a 45V switch with 2.3A peak switch current limit rating. DC1160 has overvoltage protection at 40V if the LEDs are open or not properly attached to the terminals on the PCB. The shutdown function is activated by pulling the shutdown terminal to ground.

The high side PMOS PWM dimming MOSFET can be used to achieve 3000:1 PWM dimming ratio. The board is programmed for 1MHz oscillator frequency, but can be adjusted by changing R14. Higher frequency results in higher PWM dimming ratio.

A few simple modifications can be made to DC1160 in order to convert the board from a boost LED driver to a buck mode or buck-boost mode LED driver. Please consult the data sheet for schematic details and the factory for customization details.