Design problem in compensated buck converter

Discussion in 'The Projects Forum' started by shahbaz khan, Oct 14, 2014.

  1. shahbaz khan

    Thread Starter New Member

    Mar 10, 2011
    5
    0
    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
     
  2. crutschow

    Expert

    Mar 14, 2008
    13,009
    3,233
    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.
     
    Last edited: Oct 15, 2014
  3. shahbaz khan

    Thread Starter New Member

    Mar 10, 2011
    5
    0
    Thank you very much for your help Sir. I think i must reform my circuit as it has so many jumbled up wires.
     
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