pwm generation

[sundeep2802]

i have an analog signal varying in amplitude and frequency...

here are the specifications:

16 Vp-p (approx)

requires a sweep of 1-16KHz in 20 msec

and has to be repeated every one sec.


i am using a agilent signal generator for a tringular wave at around 200KHz at 20Vp-p.

the problem here is my mesage signal has too many variations.. in few places the signal varies between +1V to -!V and in other places the signal amplitude is very high ( +8v to -8v)...

since my triangular wave amplitude is fixed i am missing out on the lower amplitude part of the signal... i am gettting pulses in places where the message signal voltage is comparable with the triangular wave...

can anybody help me put with this problem... i am running short of time.... and need desperate help...

i got drive a class d power amp...

and i generated the message signal using a microcontroller and an dac...

[classd4sure]

i am gettting pulses in places where the message signal voltage is comparable with the triangular wave...

Do you have any hysteresis on your comparator? Sounds like you might need some, turn it into a schmitt trigger.