Disclosed is a voltage converter and a method. The voltage converter includes: an input, an output, and a transformer including a primary winding and a secondary winding; a primary side circuit comprising at least one switch and coupled between the input and the primary winding; a secondary side control circuit coupled to the output. The primary side circuit is configured to receive a feedback signal from the secondary side control circuit. The secondary side control circuit is configured to generate an error signal based on an output signal of the voltage converter, and to modulate the error signal based on supplemental information to generate the feedback signal.