Apple Inc.

Liang Zhou

Vijay G Phadke

Prudhvi Mohan Maddineni

An AC-DC power supply can include a PFC stage that receives a rectified AC input voltage and produces an intermediate DC bus voltage; a DC-DC stage that receives the intermediate DC bus voltage and produces a regulated DC output voltage; and a digital controller. The digital controller can include a relatively faster DC-DC stage controller that receives DC-DC stage feedback signal(s) and produces DC-DC drive signal(s) for switching device(s) of the DC-DC stage; a relatively slower PFC stage controller that receives PFC feedback signal(s) and produces PFC drive signal(s) for switching device(s) of the PFC stage; and control logic that receives periodic output power indications of the AC-DC power supply and uses them to cause the PFC drive signal(s) to respond to a change in output power of the AC-DC power supply more quickly than would be achieved by the relatively slower PFC stage controller.

Dynamic control of AC-DC power converter PFC front end during load transients

A two-stage power converter can incorporate a buck pre-regulator and a resonant bus converter. Such a converter may be operated to achieve unconditional soft switching operation (zero voltage switching a/k/a ZVS) over a wide input and output range, while delivering excellent power conversion efficiency at lower power levels and in a no load condition.

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Liang Zhou