Patent ID: 7995361

Claim:
A flyback converter including a magnetic energy transfer element for storing magnetic energy using an excitation current and transferring the magnetic energy through a primary winding and a secondary winding, which are closely coupled to each other, a switching element connected to one end of the primary winding of the magnetic energy transfer element and configured to control current of the primary winding of the magnetic energy transfer element, a control unit for controlling the switching element through feedback, and a feedback winding of the magnetic energy transfer element, the flyback converter controlling an output voltage of a Switching Mode Power Supply (SMPS) through feedback, comprising: an error feedback circuit for detecting a period, during which a voltage of the feedback winding is higher than a reference voltage, and a period, during which the voltage of the feedback winding is lower than the reference voltage, in a flyback period of the magnetic energy transfer element, determining a difference between a ratio of the period, during which the voltage of the feedback winding is higher than the reference voltage, to the flyback period and a preset value, detecting an error of the output voltage of the SMPS, and feeding the detected error back to the control unit.