Abstract: The present paper talks about the comparison of type1, type2 and type3 controllers for isolated switch mode power supplies. The converters selected for study are Buck,Boost,Buck and boost type both in VM and CM. Small signal model is prepared for all the types mentioned above and Bode’s plot is drawn followed by stability analysis based on GM and PM. The software used for same purpose is Orcad capture Pspice.

Keywords: VM, CM, Small signal model, Stability analysis, GM, PM