Cap and transformer like inductor like component at the SMPS input

Discussion in 'Homework Help' started by bug13, Jan 8, 2013.

  1. bug13

    Thread Starter Senior Member

    Feb 13, 2012
  2. crutschow


    Mar 14, 2008
    They are for EMI reduction. The capacitor suppresses normal-mode EMI voltages and the inductive device is a common-mode choke which suppresses common-mode currents into and out of the converter but allows normal-mode currents to flow. Common-mode EMI can be generated by the high frequency switching signals from the converter being capacitively coupled to the chassis and then circulating from the chassis to the power supply ground back through the input power connection. The common-mode choke suppresses this current.
    bug13 likes this.