🚀 go-pugleaf

In article <71110@hydra.gatech.EDU>, gt3384c@prism.gatech.EDU (AUSTIN,BLANCA) writes:
|> I have been trying to generate the SPICE deck for some GaAs circuits
|> layed out using Magic. I had previously posted here and had been adviced
|> to use ext2spice instead of sim2spice. However, I am having problems with
|> the deck that ext2spice generates. Here are some of my problems:
|> 
|> 1. The devices generated are MOSFETs and mot MESFETs.
|>    What should I do? Just change the device line to correspond to
|>    the MESFET line?
|> 2. Capacitance values are too large. 
|> 3. Schottky diodes appear as MOSFETs with their drain and source tied together.
|> 
|> If I have to change the generated file so much for it to describe
|> my circuit, what is the advantage of using ext2spice over generating the
|> deck manually?

You need a special version of 'sim2spice' from UCSB to be able to extract
MESFET and capacitance correctly. The original version needs utilities
from Berkeley's original 1986 distribution tape for magic version4.X.
You will have problem compiling it if you have the version 6.X.

We have a revised version that goes with version6. It is avialable from
our anonymous FTP host "venera.isi.edu" (128.9.0.32) under pub/mosis/magic
directory. The file you need is "gaas_extract.tar.Z".

Assuming a inv.ext file exist, the procedure to use 'sim2spice' is

    ext2sim inv
    sim2spice inv.sim

Here's the resulting SPICE decks for SPICE3e...

SPICE 3 Deck created from inv.sim, tech=edgaas
*
z2 3 4 2 efet1.2 2.8
C3 3 0    0.485F
C4 4 0    1.062F
z1 1 4 3 dfet1.2 2.8
*

Hope this helps,

Jen-I pi@isi.edu :-)
MOSIS Project, USC/ISI
(310)8221511 x640