symbolic circuit simulator
Sometimes, I need to find the multi-port Z(Y,S,T) matrix
from a circuit netlist (Spice netlist).
Then the questions are:
1) Can circuit simulator(Hspice) give a multi-port Z(Y,S,T) matrix
output?
Suggestions as how to combine several 2-port matrix into
multi-port matrix technique are also welcome.
2) I not only want to find the numerical solution but also
want to find a symoblic solution. Is there any circuit simulator
being able to do that?
For example, I have a 2-port network as below
--L ------L--
|
C
|
---L ------L--
I can manually calculate the Z(Y,S,T) matrix with a
symbolic expression. But how about a network with
hundreds passive elements? Any suggestion/idea?
If there is no such kind of tool, I may consider to
write a freeware to do that. :-))
Thanks
Div
Yes, such tools exist. You should be looking for SNAP or Sapwin. Especially Sapwin has the feature you request.
Personally, i have used only the DOS-based XFUNC tool, which comes with source code and can be found at www.simtel.net and other places.
It comes from 1991, and it supports basic elements like dependent and independent current or voltage sources, ideal opamps, R-L-C etc. With these things you can build many things, like AC equivalents and so on.
All these calculate Laplace transfer functions etc
the_penetrator?
Another general purpose method is to use a SPICE simulator to perform the measurements that define the parameters you want. Drive a port and terminate all other ports with what the N port parameters require and then find the voltage, current etc and do the division. PSpice will allow frequency sweeps and math calculations in the probe window so that you can get a graph of the parameter in either rectangular or polar form.
http://www.analog-insydes.de/
It use mathmatica to calculate circuits in symbolic form .
There's one demo program to show its features .
Hi all,
There are also other tools. There is a special module for Maple caled Syrup. A collegue use it, getting quite impresive results.
ISAAC from the KUL is also a solution. Is a little heavy to use it but once you get the hint there is no problem. Results are shown in Matlab-like form.
Some time ago I also heard about Symbolic Spice. Never seen it. Try it and tell us
Regards
Humungus
Dear humungus and other fellow posters,
sspice (Symbolic Spice) is very nice, but left to a demo version (SSPICE1.0). It can handle up to 6 analog nodes. Which permits only 2-4 transistors in the circuit.
Look here: h**p://www.simtel.net/pub/pd/45184.html
The TI calculators had some minimalistic symbolic circuit analysis tools but you have to run a dongle emu in addition to the TI-calc emulator.
For XFUNC (helped me a lot!): h**p://www.geocities.com/hyiu00/ (may not work) and at simtel: h**p://www.simtel.net/pub/pd/24228.html
Regards,
the_penetrator?
The Syrup is here from Maple(R)
http://www.mapleapps.com/powertools/syrup/Syrup.shtml
Humungus:
Could you give more links about ISAAC?
Thanks
Div
hi,
This is a link to the ISAAC page
http://www.esat.kuleuven.ac.be/micas/Software/Isaac/
At the end of the page there is an email address.
I don't know if it is free.
Hi,
With pspice softawre you can simulate circuits, using Schematics of circuiit.
mems123
Dear friends,
i think normally, symbolic(analytic) analysis is not used large circuits-because of very large equation which is not handeable by human brain!,so it is possible to use demo version of soft.
also it is possible to write node-admitance matrix and give it to maple or mathematica to solve it but with a small care to do this without any bug!
another advatage to use a mathematical app. is that usually analytic equation is written to know the behavior of the circuit,and/or to optimizing it,so u can use the ability of such apps. to derivate the equations and solve them.
best...
whit tinapro is possibile a few type of simboloc simulation
to mems_123: pspice does many things but never symbolic analysis of circuits: To produce transfer functions given symbolic names to parasitics.
Gives NUMERICAL not ANLYTICAL solutions. There might be way to do parameteric sweep to overcome this and use Excel and ... but that goes too far.
to goodboy_pl: i agree. I had a current conveyor (the idea popped up from Sedra's PhD!) CCII actually. It consisted of 20 transistors, however i had to use only 6 plus ideal sources and simplifying stuff to get accurate description of some characteristics. (Gain and input resistance).
the_penetrator?
Agree that symbolic ones are usefull for small and simple circuits. For less simple ones, even after the nodal equations are solved, you still get very complex expressions which cannot be handled with cleaver approximation and substitution.
regards,
mwpro
Yes, look here: http://snap.webpark.cz
Hi,
I would like to know if some of those symbolic solver can handle distributed elements such as transmisson lines and other usual RF/MW elemetns and output S, ABCE or T matrix?
flyhigh
wHAT IS the best symbolic circuit solver does anyone know ?
(Maple, Mathematica ? ... etc)
Hi
There is also a small symbolic simulator for TI-89 and TI-92 calculators. it is called symbulator. I used it for some time and it was rather fast (than solution by hand of course) and very handy