In its various implementations including primary side and secondary side regulation, fixed switching frequency or quasi resonant operation, an isolated or non-isolated flyback topology is most often found in off-line converters for an output power ranging from a few watts up to 100 W.
The circuit operation is based on a single switch topology and the energy taken from the input is stored in the transformer’s primary inductance while the power switch is switched on, and transferred to the secondary output when the power switch is switched off.
Efficiency, power density and low stand-by power together are key requirements for flyback topologies together with reliability.
In addition to a range of controllers, power MOSFETs and integrated high-voltage converters as well as diodes and protection devices, ST offers a full set of hardware and software development and evaluation tools to help design high-efficiency, flyback AC-DC converters.
Flyback Converter block diagrams
