Apple Inc.
Input power limited switching regulator

Abstract:

This disclosure describes a system and a method to limit (i.e., regulate) the input power of a power converter as a function of the voltage and/or loading condition of a power-limited source such as a battery. In some embodiments, the power converter may comprise a transconductance amplifier that may produce a sink current to a current mirror, which in turn that may provide an adjusted current limit threshold to the power converter. The power converter may utilize the current limit threshold to perform cycle-by-cycle current limiting, thus regulating the input power drawn from the battery.