PWM Driver for High Power RGB LEDs

Overview

A combination of a PIC and three constant current buck converters is the design of this circuit to create the RGB LED controller that drives the high power 350mA LEDs using PWM to control the brightness of the LED.

Explanation

The controller can generate up to 16 million colors using static effects, strobe, and fades by driving the red, green, and blue LEDs with varying pulse widths. This project is a revised version with dimensions that are approximately the same while using a double-sided PCB. The components for the RS232 serial interface and second push button were removed as well as the series resistor and power-on LED. To eliminate the need for a jumper on the ICSP header in normal operation, a 22K resistor is added between MCLR input and Vdd.

The anode of the RGB LEDs connects to the inductor and the cathode to the track that disappears under the ZXLD1350’s. The pad size for the three inductors is SM2512 although there are several types of inductors that can be used. The 5-pin ICSP header needs soldering on the component side of the PCB and the middle pin also on copper side.