Impedance Measurements for Multiphase Converters

Measuring the output impedance of a DC/DC converter and matching it to the supplied load can be an important step in designing an optimal switched-mode power supply (SMPS), especially in voltage regulator module (VRM) applications. The available methods for obtaining bounds on its frequency dependence are analytical, experimental and simulation. This paper tries to evaluate the available methods along with its pros and cons for a multiphase dc/dc converter used in a VRM application.