RGB LED PWM Driver Based on Power MOSFET

Overview

A logic level N-channel high power MOSFET is used to create this RGB LED driver that would allow LED arrays or lamps of up to 5A per channel to be controlled without heatsink installed.

Details

A PIC16F863 is used to control the main unit as the supply voltage is in the range of 9 to 24V in order to operate the circuit. This voltage range is dictated by the input requirements of the capacitors and 78L05 voltage regulator. The input power to the board must be regulated DC and be capable of supply from the power requirements of the output load.

This version uses high power MOSFETs capable of sinking 5A on each channel without heatsinks although the circuit is essentially the same as the smaller RGB driver using the 5mm LEDs. The PCB screw terminal connectors are rated at 16A while the individual MOSFETs could handle more current. The total load for the three RGB channels should not exceed this rating since there is only a single Ground connection to the board.

The negative terminals of LED arrays should be connected to the MOSFET outputs and the positive to common.