Feedback voltage modulation to reduce power converter quiescent current

A power converter, comprising:

• a primary side controller at a primary side of the power converter;
• an optocoupler circuit that provides a feedback signal from a secondary side of the power converter to the primary side controller, the feedback signal being representative of an output level of the power converter;
• and
• a primary side switch at the primary side of the power converter, the primary side switch being controlled by the primary side controller based on a voltage amplitude of the feedback signal;
• wherein the primary side controller is operable to:
• allow a voltage amplitude of the feedback signal to rise towards a voltage amplitude that is greater than or equal to a first threshold voltage level in response to determining that the power converter is in a no-load or ultra-light load mode of operation;
• issue a first sequence of one or more enabling pulses to the primary side switch to reduce a voltage amplitude of the feedback signal in response to determining that the voltage amplitude of the feedback signal is greater than or equal to the first threshold voltage level;
• enter a normal mode of operation of the power converter in response to determining that the voltage amplitude of the feedback signal is greater than or equal to a second threshold voltage level;
• and
• issue a second sequence of one or more enabling pulses to the primary side switch of the power converter during normal operation of the power converter, the voltage amplitude of the feedback signal being less than the first threshold voltage level during the normal mode of operation of the power converter.