ABSTRACT
The conduction loss of the diode rectifier contributes significantly to the overall power loss in a power supply, especially in low output voltage applications. The rectifier conduction loss is proportional to the product of its forward-voltage drop and the forward conduction current. On the other hand, operating in the MOSFET III quadrant, a synchronous rectifier presents a resistive characteristic, as shown in Figure 12.1. Under a certain current level, the forward voltage drop of a synchronous rectifier can be lower than that of a diode rectifier, and consequently reduces the rectifier conduction loss [1]. Due to the fact that synchronous rectifiers are active devices, the design and utilization of synchronous rectification needs to be properly addressed.
