Fast recovery diode (FRD) is a kind of semiconductor diode with good switching characteristics and short reverse recovery time. It is mainly used in switching power supply, PWM pulse width modulator, frequency converter and other electronic circuits, as high-frequency rectifier diode, freewheeling diode or damping diode. The internal structure of the fast recovery diode is different from that of the ordinary PN junction diode.

Battery powered portable devices are more and more important in today's life. This trend also depends on the development of high-energy storage technologies, such as Li ion batteries and supercapacitors. These energy storage devices are connected to renewable energy systems (solar and wind energy) to collect and store energy and provide it to users stably. Some of these applications require fast charging or discharging.