Method and apparatus for sensing multiple voltage values from a single terminal of a power converter controller

A controller for a power converter, comprising:

• a switching control coupled to switch a power switch of the power converter to regulate an output of the power converter;
• and
• a sensor coupled to receive a signal from a single terminal of the controller, wherein the signal from the single terminal is representative of a line input voltage of the power converter during at least a portion of an on time of the power switch, wherein the signal from the single terminal is representative of an output voltage of the power converter during at least a portion of an off time of the power switch, and wherein the switching control is responsive to an output of the sensor, the sensor further comprising:
• a first current source;
• an internal voltage supply coupled to the first current source;
• and
• a buffer circuit coupled to receive the signal from the single terminal, wherein the first current source is coupled to supply a first current to the buffer circuit.