Pulse Sharing: Achieving High Efficiency and Excellent Regulation in Multi-Output Flyback Power Supplies

Abstract:
This paper introduces a pulse sharing control strategy which is a key innovation employed in the InnoMu (TM) -2 IC family of multi-output flyback converters from Power Integrations. InnoMux-2 ICs enable a unique flyback architecture, enabling a multi-output design that can adjust to changes in line and load without affecting the other outputs and eliminate the effects of cross regulation. Pulse sharing eliminates audible noise and reduces fluctuations in power output by distributing energy between outputs in each switching cycle. This article will explore the design challenges associated with this strategy, it will cover how the approach effectively accommodates sudden changes in power demand (load transients) and reduces EMI by adding variations in operating frequency (jitter).