I have some PIC18F4550s lying around, and I want to play with the USB features of this chip, therefore I made this breakout board. It contains enough components to get the PICMicro running, and nothing more, all the pins are routed to pin-headers to use with an experimenter board.


  • ICSP connector (In-Circuit Serial Programming, AKA PicKit 2 & 3)
  • USB-B Connector
  • 20Mhz clock crystal

Eagle files:  PIC18F4550 USB ICSP breakout board

I have built and tested, the revised version of, both the positive, and the tracking negative regulator. The new version is here:

I have not included Q12, since it was part of the original current limiting circuit. The pass transistors Q5 and Q7, are mounted off-board, on a suitable heat sink. R18 adjusts the maximum output voltage, and R17 adjusts the voltage of the negative tracking regulator.

I will do some more testing of the power supply under different load conditions, and post the results.

LAB power supply Eagle files

I just thought I would publish design of the now deceased DAC, this is simple and easy to build, as it was my second working DIY project. Consider a better supply for the TDA1543 chip.

Shematic (PDF), PCB Layout (PDF), and Cadsoft Eagle 5.0 files

Generated on 2018-05-03 01:14:21.936204