Communication circuit for flyback power converter with synchronous rectifier

A method for communicating with a power converter comprising:

• receiving at a primary side of the power converter, a one or more data bits from a secondary side of the power converter, by sensing a respective data distortion of a sensed waveform for each data bit during a discharge period of power transfer cycle of the power converter, the sensed waveform being proportional to a secondary current of the power converter;
• and
• decoding the one or more data bits to determine a response of the power converter.

A communication circuit for a power converter comprising:

• a primary circuit connected to a primary side of the power converter, and configured to sense a distortion of a waveform with a detection circuit to detect a data bit, the waveform proportional to a secondary current of the power converter;
• and
• a secondary circuit connected to a secondary side of the power converter, and configured to encode a protocol message as a data bit, wherein the protocol message is received from a sink device connected thereto, and to communicate the data bit to the primary circuit by distorting the secondary current to represent one state of the data bit and by not distorting the secondary current to represent another state of the data bit.