Microchip Technology Inc

AN874

Title:
Buck Configuration High-Power LED Driver
Name:
AN874
Date:
02/10/2006
Author:
Keith Curtis
Description:
The circuit and firmware described in this application note demonstrate a minimal parts count driver/controller for a LumiLED? LED. The circuit is based on a buck topology switching power supply using the on-chip comparator peripheral within the PIC12F675 microcontroller. The switching power supply design ensures efficient power transfer between the system battery and the output LED. Using the attached Flash microcontroller as a control for the driver circuit expands the capability of the circuit to include intensity control, automated intensity compensation for low battery conditions, and the ability to playback preprogrammed Flash sequences. The Flash microcontroller also allows the creation of a custom PC-based graphical user interface, using the PICkit? Flash Starter Kit for programming the preprogrammed Flash sequences. The combination of the switching power supply design and the microcontroller results in an efficient circuit with advanced automated features while keeping the circuit simple and inexpensive.
Keywords:
AN874, Buck, Comparator, Flash, Flashlight, high current, LED driver, LumiLED, Luxeon, PICkit, power supply, switching
 
 Application Notes & Source Code
 Last Updated
Size
 
  AN874
  02/10/2006
  349KB
  AN874 Source Code
  02/28/2005
  25KB
  Programming GUI
  03/14/2004
  2959KB