Patent ID: 8860397
Filing Date: 2014-10-14
Classification: H02M,Y10T

Abstract:
1. A power controller circuit configured to control a power switch that provides a regulated output and has a switch control input, comprising: a low voltage detection circuit to receive a combined rectified alternating current (AC) voltage provided by a first rectified AC input voltage combined with a second rectified AC input voltage; said low voltage detection circuit configured to output a low voltage indication signal upon detection of an initiation of an increase of the combined rectified AC voltage said low voltage synchronization circuit including a diode having a first port configured to receive the low voltage indication signal and a second port; a low voltage synchronization circuit configured to receive and condition the low voltage indication signal and to output a synchronization pulse; and a hysteretic regulator circuit configured to receive the synchronization pulse and, in response, to output a drive signal to the switch control input of the power switch to turn on the power switch, said hysteretic regulator circuit having a comparator circuit comprising: a first input configured to receive the synchronization pulse and coupled to said second port of said diode of said low voltage detection circuit; a second input coupled to a reference voltage source; and a first output configured to output the drive signal in response to receiving a voltage at said first input that satisfies a voltage threshold defined, at least in part, by the reference voltage.