Hello Everyone!
I am working on practical design of Buck converter with PI Compensator. I want to step down a voltage range of 20-30Vdc to 10Vdc. My Circuit works fine in steady state region but there are some spikes generated at the switch on/off points and consequently output voltage also consists of these switching transients. I tried to apply RCD to the mosfet switch, TVS at load side, applied bypass capacitors at Vcc and Vss with op-amps (AD-712) but still having the same problem. Does anybody know the reason for this? Please help me...Thanks

 

Large output spikes in a switching regulator are usually caused by poor layout and decoupling. For lowest noise you need a circuit board with a ground plane, with all devices decoupled directly to the ground, and the circuit laid out so the high switching currents have a short path. Here's a discussion of that.

 

Thank you very much for your help Sir. I think i must reform my circuit as it has so many jumbled up wires.