Sünkroonisreti

Sünkroonisreti, often referred to as synchronous rectification, is an electronic technique used to improve the efficiency of switching power converters. In a typical switching power supply, a diode is used to conduct current during the freewheeling period. Diodes, however, have a forward voltage drop, which leads to power loss and heat generation. Sünkroonisreti replaces this diode with a semiconductor switch, such as a MOSFET.

The key to sünkroonisreti is controlling the MOSFET to turn on and off at the precise moments when the diode would have conducted. This synchronization ensures that the MOSFET conducts only when needed, effectively acting as a low-resistance path for current. By using a MOSFET with a significantly lower on-resistance than the forward voltage drop of a diode, the power loss during the freewheeling period is substantially reduced.

This technique is particularly beneficial in applications where high efficiency is critical, such as in low-voltage, high-current power supplies, battery-powered devices, and server power supplies. The improved efficiency translates to less wasted energy, reduced heat dissipation, and potentially smaller and lighter power supply designs. Implementing sünkroonisreti requires careful control circuitry to accurately synchronize the switching of the MOSFET with the switching of the primary power stage.