Phase synchronization techniques in multiphase hysteretic controlled switching power converters

Hysteretic control is well known for fast transient response and superior stability, but usually exhibits a variable switching converter. Hence, when it is applied to a multiple phase switching converter, phase synchronization can be challenging, especially at high switching frequency. This paper reviews various phase synchronization approaches. A delay-locked loop (DLL) with adaptive duty cycle modulation in each phase is detailed for both the accurate synchronization and the balanced current sharing.