Techniques for controlling a power converter using multiple controllers

A controller configured for use with a power converter and a power switch comprising:

• a primary controller coupled to an input side of the power converter and configured to control the power switch to transfer energy from the input side to an output side of the power converter, wherein the primary controller further comprises a primary switch control circuit configured to control the power switch in response to a primary switching pattern signal;
• and
• a secondary controller coupled to the output side of the power converter and configured to transmit a control signal to the primary controller through a communication link, the secondary controller configured to initiate a transition operation with the primary controller through the communication link, wherein the transition operation is representative of a transfer of control of the power switch from the primary controller to the secondary controller and the primary switch control circuit is configured to detect that the transition operation has been completed responsive to the control signal being received relative to a switching event of the power switch, wherein the secondary controller further comprises:
• a secondary switch control circuit configured to output the control signal to the primary controller in response to an output of the power converter;
• a charging circuit coupled to an energy storage element for providing power to the secondary switch control circuit;
• and
• a voltage detection circuit coupled to the energy storage element, wherein the voltage detection circuit is configured to enable the secondary switch control circuit to initiate the transition operation.