Combining synchronous rectification and post regulation for multiple isolated outputs

A novel secondary side topology is presented for the simultaneous synchronous rectification and post regulation of multiple outputs in a single ended forward convertor. Multiple outputs are synchronously rectified and independently regulated using a simple all-MOSFET power circuit. The circuit works directly off the transformer secondary voltage, has no shoot through at turn on, and requires no bias supply and no synchronising or any other kind of signals to be exchanged across the isolation boundary. Multiple outputs with a common return are derived from the same secondary winding, leading to simple low cost magnetics. High efficiency is achieved with synchronous rectification and elimination of the intermediate DC bus. Zero current switching on the primary side is also achieved.