A flyback transformer switching power supply refers to a type of transformer switching power supply in which the secondary coil of the transformer does not provide power output to the load when the primary coil of the transformer is excited by a DC pulse voltage, but only provides power output to the load after the excitation voltage of the primary coil of the transformer is turned off. This type of transformer switching power supply is called a flyback switching power supply.

Due to its simple structure and low cost, flyback power supplies have become the mainstream solution for low to medium power isolated power supplies, but their efficiency (usually 80%~90%) and power density are slightly inferior to topologies such as forward and LLC. Its internal composition diagram is shown below:

Typical applications of flyback power supply: AC-DC power adapter (mobile phone charger, laptop power supply); Industrial power supply (PLC, sensor power supply); LED driver power supply (constant current output); Auxiliary power supply for household appliances (TV, air conditioning control board); Photovoltaic micro inverter (DC-AC conversion).

The recommended products for this type of product by ASIC Microelectronics are shown in the following figure: