From: Robert Strand
Subject: Re: Chip Info AM9709CN through AM97C11CN
Date: Sun, 08 Dec 2002 12:41:48 +1100
Organization: ihug ( New Zealand )
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NNTP-Posting-Date: Sun, 8 Dec 2002 01:43:28 +0000 (UTC)
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> Ah, a flash of insight. Back then CMOS wasn't 5 volts. More like
> anywhere in the range of 5-15 volts. Whereas TTL uses the 2.4 volt
> Looking at the table, the C versions also use about 2/3
> the power of the non-C parts.
Good point, there maybe something in that. The puzzling thing is, as I
understand it, these devices are pretty much raw JFETs with a few diodes.
The inputs are unbuffered and there is no active circuits as such. This
means the chips don't have power pins and the thresholds are determined
entirely by the JFET parameters. I'm quite certain the control inputs are
unbuffered on all versions.
All I can guess is the "CMOS" versions have thresholds ~2.5V, which are
perhaps different to the "15V Logic" versions. Now to add to the confusion
the AH50xx series show the same graphs for both the 15V and 5V logic
versions (the FET Vp is about 2.5V!), but the tabulated data shows a
different Vgs for the spec'd Rds_on. The more you look the worse it gets.
> Anybody have the 1980 National Special
> Functions databook? Or judging from the part numbers, a old AMD Linear
I think that's my only hope in resolving this once and for all but I've had
no luck finding it.
Thanks for you help, I've got a better handle on it!