Design of a transition mode controller for flyback converters

Flyback converters are widely used in consumer electronic products and other applications that require low cost isolated power supply with less than or around 200W output power. Transition Mode is one method to control the Flyback converters. This control method has the advantage of soft-switching turn-on, which greatly reduces the turn-on loss. This paper discusses the design of a CMOS Transition Mode controller. Some major function blocks will be discussed in details. Simulation result verifies the correct functionality of the controller.