Duty cycle balance module for switch mode power converter

Abstract

A duty cycle balance module (DCBM) for use with a switch mode power converter. One possible half-bridge converter embodiment includes a transformer driven to conduct current in first and second directions by first and second signals during and second half-cycles, respectively. A current limiting mechanism adjusts the duty cycles of the first and second signals when a sensed current exceeds a predetermined limit threshold. The DCBM receives signals representative of the duty cycles which would be used if there were no modification by the current limiting mechanism and signals Dand Drepresentative of the duty cycles that are actually used for the first and second signals, and outputs signals Dand Dwhich modify signals Dand Das needed to dynamically balance the duty cycles of the first and second signals and thereby reduce flux imbalance in the transformer that might otherwise arise.