DN91 Datasheet (Diodes) - Synchronous rectification improves set top box power supply efficiency

DN91, Synchronous rectification improves set top box power supply efficiency

Figure 2 shows a typical set top box power supply.

It is a cost effective design with minimum component count.

The circuit is designed to operate in Discontinuous Conduction Mode (‘DCM’) because there are lower switching losses.

Furthermore, the flyback transformer size can be reduced owing to the l

A Product Line of Diodes Incorporated DN91 Synchronous rectification improves set top box power supply efficiency Yong Ang, Diodes Incorporated Introduction This design note describes the implementation of synchronous rectification on multiple-output flyback converters.

It is focused on the low side rectification approach as shown in Figure 1 to facilitate a common drive for synchronous MOSFETs on low voltage 3.3 and 5V outputs.

The note concludes with practical measurement on a 27W four-o