LED Dimmer for Super High Brightness LEDs

This is a high-efficiency and reliability DC/DC converter with a dimming feature for super high brightness LEDs.  The project is built using L6902D chip. L6902 is a complete and simple step-down switching regulator with adjustable current limit. The current control loop with external sense resistors R6, R7, and R8 are able to work in constant current mode providing up to 350mA output current with an accuracy of 5%.  Potentiometer PR1 helps to control the dimming of the LEDs. PR1 is connected to the 3.3V reference pin of the chip. When the dimming (CS+) pin is grounded (0V) the maximum output current is provided (350mA) and vice versa when 3.3V is applied to the pin, the current provided is zero and so the LED is off.