How to create a DC power supply filter?
I am programming a microcontroller, and it worked fine. By this time, the microcontroller is powered by the USB port. After programming, i do some testing, i used LM7805 paired with wall wart as the controller's power supply. When using this power supply, the controller's behavior is a little bit unpredictable. Based on observations, the problem is the ripple in the DC supply.
I there a filter method or topology that i can use?
Note: simple capacitor filter won't work.
i have a frequency counter...
it reads 0 Hz at the USB
and reads 60 Hz at the LM7805 powered by a wall wart.