I want to power a PIC16f877 with the output from an LM7805 at +5v connected to a 9v 800mapower supply. I read on the pic16f877's data sheet that the maximum current that can be applied to Vdd is 250ma. The LM7805 data sheet just says it can deliver 1A. What i want to know is how much current will the LM7805 supply...will it be 800ma from the main supply?, or higher/lower? I just want to know if i will able to connect the output directly to the PIC without having to limit the current. Thanks.

 

not sure i fully understand, but that pic max current through vss is around 300mA, it should never draw 1 A by itself. The TO220 regulators are usually 1A max.
If you are asking about connecting the 5V output of the regulator directly to vdd of the PIC, that is fine, just use some filter caps.
hope that helped...

 

That was exactly what i was looking for. Thank you.