The internal structure of fast recovery diodes

The internal structure of fast recovery diodes is different from ordinary diodes. It adds base region I between P-type and N-type silicon materials, forming P-I-N silicon wafers. Due to the thin base region and small reverse recovery charge, not only does it greatly reduce the TRR value, but also reduces the transient forward voltage drop, enabling the tube to withstand a high reverse operating voltage. The reverse recovery time of fast recovery diodes is generally several hundred nanoseconds, with a forward voltage drop of about 0.6V, a forward current of several amperes to several thousand amperes, and a peak reverse voltage of several hundred to several thousand volts. The reverse recovery charge of the ultrafast recovery diode is further reduced, allowing its trr to be as low as tens of nanoseconds. Fast recovery and ultra fast recovery diodes below 20A are mostly packaged in TO-220 format. From the perspective of internal structure, it can be divided into two types: single tube and double tube (also known as double tube). The inner part of the pair tube contains two fast recovery diodes, which can be divided into a common cathode pair tube and a common anode pair tube according to the different connection methods of the two diodes.

fast recovery diodes with tens of amperes are generally packaged in TO-3P metal shells. Pipes with larger capacities (from a few hundred amperes to several thousand amperes) are packaged in bolted or flat form.