PWM problems

[rob_croxford]

Hi all,

I have designed a program on a pic that aswel as other things outputs a PWM signal from a voltage input. The program works prity much exactly how i want it to with 50% duty cycle being prity much exactly 50% duty cycle.

My problem is at 0% and 100%. Please see pictures.

The PWM runs at arrouns 319Hz, the +/- spikes are arround 1us long. will this be a problem in the over all working of the circuit?? can i do ne thing to make sure that at 0% there is 0V and at 100% there is full V??

Cheers for any help.

 

[(*steve*)]

Yep, that's pretty much what you should expect.

The only alternative is to turn off the PWM signal and drive the output high or low for 100% and 0%. Aesthetically it may be better, but functionally it is likely to make no difference.

 

[rob_croxford]

I thought as much, cheers Steve