Interleaved Asynchronous Delta-Sigma Modulation Concept for Dynamic Power Converters

This paper proposes a novel synchronization concept for asynchronous delta-sigma modulators (ADSM), enabling its application for interleaved operation of parallel power converter structures. Two separate first-order ADSMs are coupled via a phase-locked loop, ensuring constant phase relationship between the modulators across their switching frequency ranges. Thus, the benefits of delta-sigma modulation such as spread spectrum qualities and lower average switching frequencies compared to pulse-width modulation can be used in dynamic interleaved power converters. In this paper, we derive system equations for the synchronization loop and confirm its functionality by simulations and measurements for a two-phase interleaved half-bridge.