A new technique for spectral analysis of conducted noise of a SMPS including interconnects

The conducted EMI noise of a SMPS is predicted with two simple models for common mode (CM) and differential mode (DM) noise. Existing models are enhanced by the inclusion of PEEC models for the interconnects and voltage ringing effects at switch turn-off. PSpice frequency-domain simulations of CM and DM transfer functions are used to rapidly obtain the noise spectra. Experimental data is presented for model validation.