Input impedance investigation of a DC-DC converter on a large frequency range: A novel analytical approach

This paper proposes to investigate the Differential Mode (DM) input impedance of a DC-DC converter. This parameter is crucial for network analysis, in a wide frequency range, from very low frequency for network stability analysis up to several tens of MHz for EMC studies. Analytical approach based on signal processing theory is developed, validated by PSPICE simulations and experimental measurements. The results are discussed in comparison with an "off-line" impedance measurement, the converter being disconnected from the DC source.