Vishay was founded in 1962 by Dr. Felix Zandman with funds raised from his cousin, Alfred P. Slaner, and was named after Dr. Zandman's ancestral village in Lithuania in honor of the family members who died in the war. The company's initial products included foil resistors and foil resistance strain gages.

By 1985, the company had grown to become a leading global manufacturer of these products and began a series of strategic acquisitions to become a manufacturer of electronic components with a wide range of products. Today, Vishay is one of the world's largest manufacturers of discrete semiconductor devices and passive electronic components.

Main product lines: capacitors, resistors, inductors, diodes, transistors, transformers, MOS, power supply chips.

Fast recovery diode (FRD for short) is a semiconductor diode with good switching characteristics and short reverse recovery time, which is mainly used in switching power supplies, PWM pulse width modulators, inverters and other electronic circuits as a high-frequency rectifier diode, current-continuing diode or damping diode. Fast recovery diode internal structure and ordinary PN junction diode is different, it belongs to the PIN junction diode, that is, in the P-type silicon material and N-type silicon material in the middle of the increase in the base region I, constituting a PIN silicon chip. Because the base region is very thin, the reverse recovery charge is very small, so the reverse recovery time of the fast recovery diode is shorter, the forward voltage drop is lower, and the reverse breakdown voltage (withstand voltage value) is higher.

Structural characteristics of fast recovery diodes The internal structure of fast recovery diodes is different from that of ordinary diodes in that it increases the base region I in the middle of the P-type and N-type silicon materials, constituting a P-I-N silicon wafer. As the base region is very thin, the reverse recovery charge is very small, not only greatly reduce the trr value, but also reduce the transient forward voltage drop, so that the tube can withstand very high reverse operating voltage. The reverse recovery time of a fast recovery diode is generally a few hundred nanoseconds, the forward voltage drop is about 0.6V, the forward current is a few amperes to a few thousand amperes, and the peak reverse voltage can be several hundred to several thousand volts. Ultra-fast recovery diode reverse recovery charge is further reduced, so that its trr can be as low as a few tens of nanoseconds. 20A below the fast recovery and ultra-fast recovery diodes are mostly used in the form of TO-220 package. From the internal structure, can be divided into a single tube, pair of tubes (also known as double tube) two kinds. Pair of tubes containing two internal fast recovery diodes, according to the two diodes connected to the different ways, there is a common cathode pair of tubes, common anode pair of tubes. Figure 2(a) shows the shape and internal structure of the C20-04 fast recovery diode (single tube). Figures (b) and (c) show the shape and structure of the C92-02 type (common cathode pair tube) and MUR1680A type (common anode pair tube) ultra-fast recovery diodes, respectively. They are TO-220 plastic package, tens of amps of fast recovery diodes are generally used TO-3P metal shell package. Larger capacity (hundreds of amps ~ thousands of amps) of the tube is used in the form of bolt-type or plate-type package.