There are several design challenges associated with closing and compensating the control loop of an isolated flyback converter and the role of the TL431 voltage reference. This topic is suitable for the sessions of DC-DC converters, control, power electronics for communication applications, power electronics for computing applications, and power electronics for industrial applications. This digest will explain how an optocoupler driven by the TL431 voltage reference can be used to transmit an error signal across the isolation barrier of an isolated flyback converter in order to drive the MOSFET in the power stage. In addition, the most common mistakes and issues will be analyzed.
