FTM Board Club
HB LED Driving and Dimming Reference Design

The MCP1631HV Digitally Controlled Programmable Current Source Reference Design is used to drive and dim one or more power LEDs in a series or parallel topology (depending on the LED’s capability).

The reference design may also be used to charge one to four cell NiMH/NiCd or one to two cell Li-Ion battery packs. The board uses the MCP1631HV high-speed analog PWM controller and PIC16F616 microcontroller to generate the proper dimming ratio for LEDs or charge algorithm for NiMH, NiCd and Li-Ion batteries. The boards is used to evaluate Microchip’s MCP1631HV in a SEPIC power converter application.


• Input Operating Voltage Range: +3.5V to +16V
• Firmware default output current of 700mA with dimming ratio 10:1 (70mA/step)
• Maximum output current of 1000mA
• Maximum output power of 8.5W
• Drive one or more LEDs
• Firmware for charging Li-Ion, NiMH, and NiCd batteries
• Single ON/OFF/Dimming switch
• Status and fault indication
• Hardware and software overvoltage protection (OVP) set to 9.0V. The software value can be modified in the source code to be less than 9.0V