Constructive feedback [switched mode power supplies]

The feedback network for a flyback switched mode power supply must enable precise control of the output, but must also be inherently stable. To achieve this, the designer must manage the complex relationships between the parameters of the feedback network. Chiefly, these are the DC gain, gain margin, phase margin and bandwidth. This article presents such a feedback network with detailed descriptions of the optocoupler and error feedback amplifier sections.