Apple Inc.
Fast charge sharing between capacitors of a dual input path DC/DC converter

Abstract:

A power converter may be adapted to provide an output voltage from one of two input voltages. The power converter may include two or more buck converters that share a plurality of power converter components and each converts an individual input voltage to the output voltage. The power converter may include any of a variety of charge equalizing components that may be coupled between input terminals and optional input capacitors, which are coupled between the input terminals and ground. The charge equalizing component(s) provide(s) a fast conduction path for the equalization of input voltages and charge/voltage of the optional input capacitors. The charge equalizing component(s) can mitigate large currents created by differential voltages between the input terminals, which currents would otherwise flow through and potentially damage or destroy the power converter's switching devices.