[sdiy] Spice model for CEM gain cell

[Tim Stinchcombe]

Hi list,
	I have been looking in the archives for any help in this area,
as I want to try and model the gain cell in the CEM3320, and also the
VCA chips PA381/382: I did find some good advice - to check out Doug
Curtis's patent no. 4,004,141, which I now have a copy of. I can mostly
see how the patent applies to the 3320, but its not clear to me if it
does actually apply to the PA381/382 (there is no ref to the patent on
the datasheet), so I was wondering whether anyone knows if it actually
does or not? My main problem is that it seems to require a certain
amount of 'reading between the lines' (which my experience doesn't
stretch to yet), as I can't see if it _were_ to apply to the 381/382 how
the -2.1V DC level arises at the input summing nodes. Any insights
appreciated!

(Much to my surprise I have managed a simple macromodel of the 382 with
which I managed to simulate a quadrature oscillator, which is my
interest at the moment.)

Thanks,
	Tim
__________________________________________________________
Tim Stinchcombe 

Cheltenham, Glos, UK
email: tim101 at tstinchcombe.freeserve.co.uk