Problem with Pololu Adjustable Boost Regulator 4-25V


I’m using a Pololu Adjustable Boost Regulator in the same board as a PIC 12F863, with internal oscilator configuration at 4MHz.
Power supply is 5V, ground plane and decoupling capacitors. If I disconect the PIC, the output of the regulator gives 20V with no problem, if the PIC is working then I hear a noise like something is switching at a high frecuency, I see serious ripple in both input and ouput voltages (voltage is very stable if the PIC is not working), and everything goes crazy (pic outputs and so on…).

Any idea of what it can be wrong?

Thanks for your help.


It’s difficult to tell without knowing more about your circuit, but generally, it sounds like you don’t have enough power or decoupling. Have you looked at your power supply with an oscilloscope?

- Jan