FRED Module

The internal structure of the fast recovery diode module is to add base region I between p-type silicon material and n-type silicon material to form pin silicon wafer. Because the base region is very thin and the reverse recovery charge is very small, not only the TRR value is greatly reduced, but also the transient forward voltage drop is reduced, so that the tube can withstand a high reverse working voltage.

The reverse recovery time of fast recovery diode module is generally hundreds of nanoseconds, the forward voltage drop is about 0.6V, the forward current is several amperes to several thousand amperes, and the reverse peak voltage can reach hundreds to several thousand volts. The reverse recovery charge of ultrafast recovery diode module is further reduced, so that its TRR can be as low as tens of nanoseconds.

The fast recovery diode module has the characteristics of high voltage resistance, low leakage current during reverse blocking, low on state resistance and high current in the forward direction. Because it is used as a switch, it is generally required to have a fast switching speed. In addition, properly selecting the characteristics of freewheeling diode, especially the reverse recovery characteristics, such as reverse recovery time and reverse recovery flexibility, can significantly reduce the power consumption of switching devices, diodes and other circuit elements, and reduce the voltage spikes and electromagnetic interference caused by freewheeling diode, so as to minimize or even remove the absorption circuit.

Generally speaking, the forward voltage drop of the fast recovery diode module is small, about 0.4V, while the common silicon tube is about 0.6V. In order to reduce the loss, the fast recovery diode module is used.