Patent ID: 9742288
Date: 2017-08-22
CPC Classifications: H02M,Y02B

Claim:
1. A control circuit for use in a power converter having an energy transfer element for transferring energy between an input side and an output side of the power converter, the control circuit comprising a first controller to be coupled to the output side of the power converter and an output ground reference, the first controller including: a switch control signal generator to be coupled to receive a feedback signal that is representative of an output of the power converter and configured to communicate a control signal to a second controller coupled to the input side of the power converter and an input ground reference, wherein the input ground reference coupled to the second controller and the output ground reference coupled to the first controller are different, wherein the control signal is communicated to the second controller via a communication link to initiate a transition of a switch on the input side of the power converter from an OFF state to an ON state to regulate the transfer of energy from the input side of the power converter to the output side of the power converter after the switch control signal generator receives an enable signal and if the feedback signal indicates a change in the output of the power converter; and an extremum locator coupled to generate the enable signal to enable the switch control signal generator to communicate the control signal to the second controller in response to a first signal that is representative of an instantaneous voltage on an output terminal of the energy transfer element that oscillates in response to an ending of the transfer of energy to the output side of the power converter, and wherein the extremum locator enables the switch control signal generator such that the transition of the switch from the OFF state to the ON state occurs substantially at a time that the first signal reaches an extremum.