Method and apparatus for power converter fault condition detection

A power converter, comprising:

• an energy transfer element coupled between an input and an output of the power converter;
• a switch coupled to the energy transfer element;
• and
• a controller coupled to control switching of the switch to regulate the output of the power converter, wherein the controller includes:
• a control coupled to generate a drive signal to control switching of the switch;
• a sensor coupled to receive a signal from a terminal of the controller, wherein the signal from the terminal is representative of an input voltage of the power converter during at least a portion of an ON state of the switch, and is representative of an output voltage of the power converter during at least a portion of an OFF state of the switch, wherein the sensor is configured to sample the signal from the terminal during the portion of the ON state to generate a first sample signal and to sample the signal from the terminal during the portion of the OFF state of the switch to generate a second sample signal;
• and
• a fault detector coupled between the sensor and the control, wherein the fault detector is coupled to detect a fault condition of the power converter in response to either the first or the second sample signal, wherein the control is coupled to inhibit the switching of the switch to reduce a power output level of the power converter in response to the fault detector detecting the fault condition.