Enabling circuit for avoiding negative voltage transients

摘要

An enabling circuit includes a comparison circuit configured to compare a feedback signal representative of a charge of an energy storage element of a regulating circuit with a reference charge and provide an output in response to the comparison to enable the regulating circuit to switch from a first state to a second state if the charge of the energy storage element is less than the reference charge. The enabling circuit may also be used to enable a synchronous rectifier converter to provide a charging current to a battery in a battery charging system of an electronic device thereby avoiding negative voltage transients that may otherwise occur at the output of the synchronous rectifier converter. Various methods are also provided.