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Downloadable Advanced Diode Recovery Model Paper

Someone asked me for information on an ancient (1991?) Spice-based soft reverse recovery and forward recovery junction diode model I developed with colleagues including Mark A. Johnston (Where are you now Mark?  I can't find you now.  I hope you are well!).  Update: Mark recently ran across this web page and contacted me!  I eventually created a documentation file many years later to explain this old model, but never quite finished it until now. 

I just recently "fixed it up" a bit to make it at least reasonably presentable
and you can now view the completed document by clicking on the link here or at the bottom of the page.

Some notes:

- This diode model is aimed at emulating the characteristics of (mostly higher voltage) PIN diodes.  Such diodes incorporate a middle "I" region (standing for Intrinsic, but usually are just lowly doped).  This model won't be particularly useful for typical "lower voltage" diodes such as those with less than ~100v maximum reverse voltage.  For such lower voltage diodes the stored charge effects are typically much less evident because any stored charge can be very quickly altered by the external circuit.  This is because the junction depletion length for lower voltage diodes is much shorter (implying less forward-current charge storage), and the doping levels are much higher (and thus the resistance in series with the depletion region is small).

- This is a VERY old model. I'll bet many others have developed much better techniques by now, but I'll not be looking for them - you'll need to look yourself.

- This is an empirical, seat-of-the-pants, measurement-based Spice circuit model.  You may need to do some moderately difficult device measurements to parameterize such a model (choose actual model parameter values for a specific device).  But the good news is that we hardly mention any semiconductor physics!

- The documentation file linked below is long and wordy but it shouldn't be overly hard to understand for most electrical engineers (note the "we hardly mention any semiconductor physics" above).

- It's been about 20 years since I looked for simulator program models that include soft reverse or forward recovery.  Some simulators may have implemented much-improved models since then.  But the (mostly) old document below may still yield some insight into practical diode recovery effects and modeling.  Please keep in mind that this documentation was based on standard SPICE capabilities available in 1991!

- No guarantees on these techniques (but they worked pretty well for me... AND there's lots of possible improvements you might make!).  If you do, I'd appreciate a link or email.

NOTE: In order to download this file you "may" need to open it up by clicking on the link, then use the "printer icon" (on the top left?) to save it as a pdf to disk (and I don't know why the file save name is weird but I think you can change that before you download).  Google Sites pages (like mine here) just seem to have strange and unpredictable behavior for files attached to pages. 

You "should" be able to download this pdf file by clicking on the link at the below left OR on the "down arrow" at the bottom right.  But I've had a lot of problems using Google Sites file downloads.

If clicking on the link above or the "down arrow" at the bottom right doesn't let you download the file, send me an email request (from, or including somehow, an email address you want me to send it to) to rstevescott@gmail.com and I will send you an email including the file as an attachment.  I won't use your email address for anything else.

Best wishes.

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Copyright © 2014 Robert Steven Scott

Robert Scott,
May 15, 2014, 12:25 PM