Whats a switching diode?

[slackjack]

I've heard this term somewhere, but I'm unsure as to what a switching diode actually is. Can someone please explain it to me.

--thank you.

 

[audioguru2]

A switching diode has a small junction for low capacitance so it can switch quickly like a 1N914 or 1N4148 which can pass 100mA.
A rectifier diode has a large junction for good cooling but has a high capacitance so switches slowly like a 1N400x which can pass 1A.

 

[indulis]

It also relates to the reverse recovery time... in the case of a switching diode, Trr is "fast".

Besides rectifier diodes, and general purpose diodes, there's the Schottky, no Trr, a lower forward voltage, but a much higher junction capacitance.

 

[prateeksikka]

These are special purpose diodes which have small  charge storage time which enables them to work at very high(microwave frequencies)
;D

 

[indulis]

There isn't anything very "special purpose" about switching diodes, as Audioguru points out in mentioning the 1N914 and 1N4148, which are quite common/generic.

Semiconductors in general, that are used at microwave frequencies are COMPLETELY DIFFERNT ANIMALS.

 

[abhishek gupta]

as the name indicates,it is device which is used in electric devices as fast on -off switch.when diode is in forward bias condition then the diode is in on state i.e.the electric ckt is on and if diode id in reverese bias state then diode is in off state i.e. electric ckt is in off state.thus doide will act as a switch and hence caled as switching diode.

 

[Ughadoo]

Switching diodes are fast diodes that show low losses when used at medium/high frequencies.

 

[indulis]

... when diode is in forward bias condition then the diode is in on state i.e.the electric ckt is on and if diode id in reverese bias state then diode is in off state i.e. electric ckt is in off state.thus doide will act as a switch and hence caled as switching diode.

This is a little misleading in that ALL diodes exhibit this phenomena, forward bias-on, reverse bias-off, not just switching diodes... the "switching" part of the name refers to speed as it relates to reverse recovery, not it's "action"!! There are also diode's which exhibit a "soft" reverse recovery characteristic, and some with a "ultra-fast" recovery characteristic. Diodes like the 1N914 and 1N4148 are lumped into a catagory called "small signal diodes".