All About Circuits Forum  

Go Back   All About Circuits Forum > Electronics Forums > General Electronics Chat


General Electronics Chat Discussion forum for general chat about anything electronics related, including asking questions about material in the All About Circuits E-book, Worksheets, and Videos.

Reply   Post New Thread
Thread Tools Display Modes
Old 05-02-2008, 12:56 AM
wkyong wkyong is offline
Junior Member
Join Date: Apr 2008
Posts: 33
Smile what is the meaning of the term 'reverse recovery time" for diode?

What is the meaning of the term 'reverse recovery time' for diode?
What is soft recovery & fast recovery?Are they same?
Reply With Quote
Old 05-02-2008, 01:04 AM
Papabravo's Avatar
Papabravo Papabravo is offline
Senior Member
Join Date: Feb 2006
Location: Michigan, USA (GMT-5)
Posts: 5,850

Reverse Recovery Time is the time it takes a diode to reduce the reverse current to zero when going from forward bias to reverse bias. Contrary to popular opinion and idealized models diodes do conduct in the reverse direction, but only for a short while.

A fast recovery diode has a smaller reverse recovery time than a standard diode.

I'm not familiar with the term soft recovery, but it sounds like it should be slower and less abrupt.
We never have time to do it right,
But we always have time to do it over.
Reply With Quote
Old 05-02-2008, 02:54 AM
Caveman Caveman is offline
Senior Member
Join Date: Apr 2008
Location: Austin, TX
Posts: 471

The reason for reverse recovery is that a diode is a minority carrier device. It takes a certain amount of time for them to recombine.

Fast recovery diodes were designed for use in switching applications such as switching power supplies to reduce the recovery time. If you use a standard recovery diode in a switching power supply, the diode will cause enormous inefficiencies.

However, it was later realized that having a very fast recovery time caused other issues with switching power supplies. I can't remember exactly what it was, but it had something to do with its interaction with the switching FET. To fix this, soft recovery diodes were developed. They recover quickly but with a softer return to zero current.
Reply With Quote
Reply   Post New Thread


Related Site Pages
Section Title
Worksheet Special diodes
Worksheet Rectifying diodes
Textbook The DIAC : Thyristors
Video Lecture Special Diodes - Varactor Diodes - Diodes and Diode Circuits
Video Lecture Diode Characteristics - Diode and Diode Circuits - Diodes and Diode Circuits
Textbook Special-purpose diodes : Diodes And Rectifiers
Textbook Zener diodes : Diodes And Rectifiers
Textbook Inductor commutating circuits : Diodes And Rectifiers
Textbook Diode ratings : Diodes And Rectifiers
Textbook Introduction : Diodes And Rectifiers

Similar Threads
Thread Thread Starter Forum Replies Last Post
Schottky diodes and reverse recovery time SkiBum326 Homework Help 0 07-19-2014 09:28 AM
Reverse Recovery for High Power Press-pack/Hockey puck devices kkumar6 Electronics Resources 1 03-22-2013 08:49 PM
How to compare reverse recovery time between diodes in different test conditions? NicksonYap General Electronics Chat 2 01-14-2013 02:55 AM
force reverse recovery TAKYMOUNIR General Electronics Chat 1 08-14-2011 10:21 PM

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT. The time now is 11:04 AM.

User-posted content, unless source quoted, is licensed under a Creative Commons Public Domain License.
Powered by vBulletin
Copyright ©2000 - 2014, vBulletin Solutions, Inc.