Practical issues of input/output impedance measurements in switching power supplies and application of measured data to stability analysis

Measurements of converter input and output impedances are conducted to verify that the power system has been correctly modeled and designed. Many impedance measurement setups presented in the past are useful for tutorial purposes, but in practice their application is limited to low-power supplies. This paper presents practical impedance measurement circuits, which provide reliable measurements for a wide class of power supplies. The measured impedance data was applied to stability analysis of the computer distributed power system.