Output impedance of high performance current mode dc-dc buck converters, with applications to voltage-regulator module control combinations

Voltage regulator modules (VRMs) comprising parallel interleaved buck converters can be controlled by current-mode methods to achieve low dynamic output impedance. A two-phase VRM is designed using both sensorless current mode (SCM) and peak current mode (PCM) control. SCM control for one phase provides a means of achieving low output impedance for the parallel converter system. PCM is used to control the other phase, without output voltage feedback, to enforce current sharing between the phases. In this configuration, SCM and PCM are exploited for their natural reference tracking capabilities: voltage and current, respectively.