FEEDBACK COMMUNICATION TECHNIQUE FOR SWITCHED MODE POWER SUPPLY

摘要

A power conversion circuit for a switched mode power supply (SMPS) 11 is arranged to be switchable between a normal mode of operation and a burst standby mode of operation. In an embodiment, the SMPS 11 comprises an AC/DC stage having a primary (input) side and a secondary (output) side of a transformer 12. A switched mode power stage has a controller 15 on the primary side for controlling the switching of power to the secondary side. The controller 15 has a control input 3 for receiving feedback signals from a feedback circuit 50 on the secondary side of the transformer 12. The SMPS 11 comprises an opto coupler 20 arranged to communicate to the control input 3 of the controller 15 a feedback signal which indicates the start and the end of a switching cycle in the burst mode . Advantageously, this allows the SMPS 11 to react quicker to loads applied when in the burst standby mode.