From: Jim Thompson
Subject: Re: SPICE and amp stability
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Date: Thu, 21 Nov 2002 15:07:53 GMT
NNTP-Posting-Date: Thu, 21 Nov 2002 10:07:53 EST
Organization: Cox Communications
On Thu, 21 Nov 2002 14:24:02 GMT,
Fred Bloggs ,
In Newsgroup: sci.electronics.design,
Entitled: "Re: SPICE and amp stability",
Wrote the following:
|Jim Thompson wrote:
|> If you're using PSpice, you can download, from my website, my
|> "Loopgain" part. This performs two passes, one with voltage drive,
|> and one with current drive, then computes gain and phase; all done
|> without perturbing the loop.
|> This *may* be applicable to other "Spices" as well.
|What is the problem that you cannot paste the ASCII file here? This is
|not quite applicable to all simulators exactly but it can be done as two
|runs with separate macros. I assume you are referring to the R.D.
|Middleton * ingenious * technique of determining the Ti and Tv loop
|transmission functions from which the composite T+1=(Ti+1)||(Tv+1)- it's
|a good one...
Fred, I modified Middleton's derivation by hand to make it applicable
to simulators, then scanned it into a PDF. Unfortunately the PDF is
the largest portion of the ZIP file. So you'll need to download it to
see it. (I'm not patient or skilled enough to do equations in a word
Here's the macro file for PSpice:
PL1 = V(LG)@1
PL2 = V(LG)@2
QL1 = I(VMAC)@1
QL2 = I(VMAC)@2
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| Jim-T@analog_innovations.com Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |
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