[sdiy] Replacing CA3080 with CA3046 ??

[srnovak at ncsu.edu]

Another thought in comparing MAT04 with CA3046 is that each chip was
designed for it's technology (i.e. junction isolation Vs. trench
isolation). The Collector-Emitter breakdown voltage of the MAT04 is 40V,
where the Colector-Substrate breakdown voltage of the CA3046 is 20V min
and typical is 60V. I was planning on running off single 12V, but even
with a dual 12V supply, it seems both chips would be in no danger of
parisitic diodes or BJT's as long as the substrate was at the lowest
voltage (also assuming I have a little better then the worse CA3046).

	From: 	  patchell at cox.net
	Subject: 	Re: [sdiy] Replacing CA3080 with CA3046 ??
	Date: 	April 8, 2005 11:12:09 PM EDT
	To: 	  samppa.tolvanen at gmail.com, madhun2001 at yahoo.com
	Cc: 	  srnovak at ncsu.edu, synth-diy at dropmix.xs4all.nl

The MAT04 is dialectically isolated (the CA3046 is junction
isolated)...also, the THAT 3xx transistor arrays are dialectically
isolated, so you don't have to worry about which pin is more negative that
which...

However, in general, building your own OTA is sortof a loosing
proposition.  However, I have made simple OTA's, using a THAT340 PNP/NPN
array (two NPN's and two PNP's) that work out pretty good for cloning the
SSM2040 VCF...still...it is a rather expensive solution...

        -Jim

At 03:13 AM 4/9/2005 +0300, Samppa Tolvanen wrote:
On Apr 9, 2005 1:43 AM, Tim Ressel <madhun2001 at yahoo.com> wrote:
> Yo,
>
> Don't forget the oft overlooked pin 13 requirement.
> The substrate of the IC (pin 13) needs to be at the
> lowest voltage the part is likely to see. Otherwise
> some internal dides conduct and spoil the party. Keep
> this in mind when designing Q5 into your circuit.
>
> --Tim Ressel (rubbing the scar where he was bit...)
>
´
Could MAT-04's have some "bias". pleaseee? LIke a negative one-- down
there.. anx, Samppa
å.s. Down  I went

        -Jim
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