how to get clean waveform? how to avoid overshoot/undershoo

[ferrite]

Hello:

Recently I made one socillator and one pulse generators,
but all of them suffers from un-clean waveform. There are
some clear overshoot/undershoot on some waveforms I get.

I think I have added enough bypass capacitance on the
circuit board. Especially to the pulse generator,
it has a copper ground plane which I thought should be
able to reduce over/undershoot a lot, but
I am some disappointed with the result.

I apply bypass capacitors(0.1uF) for each IC I used on the
board and for the output, I use 0.1uF+0.01uF.
Also on the supply pins of board, I put a quite big
elctrolytic 22.7uF.

I will very appreciate your help on this issue...

Thanks

 

[rfmw]

Re: how to get clean waveform? how to avoid overshoot/under

Post the schematics so that we can see what's your circuit of the oscillator and pulse generator. You've done proper bypassing, but the problem seems to be elsewhere.

 

[dumbfrog]

Re: how to get clean waveform? how to avoid overshoot/under

reduce the current loop of the power supply because L proportional to current loop

 

[electronics_kumar]

Re: how to get clean waveform? how to avoid overshoot/under

in control sysstem perspective,
you can use a derivative controller(based on RC element) to eliminate overshoot.

 

[ferrite]

Re: how to get clean waveform? how to avoid overshoot/under

in control sysstem perspective,
you can use a derivative controller(based on RC element) to eliminate overshoot.

can you give more details? what is a derivative controller?
and how?

 

[electronics_kumar]

Re: how to get clean waveform? how to avoid overshoot/under

derivative controller is a differentiator

 

[qutang]

decrease the speed of opamp.

 

[extraord]

Re: how to get clean waveform? how to avoid overshoot/under

from the frequency domain of view, that's cause by complex poles in circuit.
reduce the image part of them, you will get a better solution.