State-space analysis of the cross-regulation

Abstract

Multiple output switching regulators using cross-regulation method are useful power supplies for electronic equipment which requires several regulated and isolated voltages. However, there appears some steady-state error on the crossregulated output voltages even though all windings of the reactor are ideally coupled. In this paper, the precise analysis for the cross-regulation phenomenon is performed by means of state-space averaging method. From this analysis, we clarify that the cross-regulation error arises due to the internal resistances of the circuit. Furthermore the dynamic characteristics such as the frequency responses and the stability are analyzed in detail.