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-output set top box power supply to
demonstrate that a 3% efficiency improvement over a Schottky solution can be achieved with the
aid of the ZXGD3101 synchronous
MOSFET controller.
KBP 206 G BR
R9 ...