Message from discussion Deja-vu redesign task
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From: pedro <inas...@work.net>
Subject: Deja-vu redesign task
Date: Mon, 08 Oct 2012 12:16:47 +0800
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I am likely to be tasked with "recreating" a board/design from the
mid-70's which (among other considerations) used some long-obsolete
Fairchild 9000 series chips. At the time, these were chosen for their
speed and functionality.
This board is part of a multi-board setup, and as such retaining the
original "block diagram functionality" is essential.
95H28 - Dual D flipflop that happily clocked at 250 MHz when
configured as two cascaded /2 stages. Anything dual-D - preferably
DIP - that goes that fast and is readily available would suffice.
9504 - a quad triple-input OR gate in a DIP-16, with one input per
gate commoned as an enable. Followed the above, max Fin was 70 MHz in
the application. As all pins are employed in the existing design,
finding a single-chip replacement block is proving a challenge.
Also used the Motorola MC10216 which I can't find "out there". (The
application ran faster than the 10116). The role is a limiting amp
with inputs to 250 MHz.
There was also an 11C90 or 95H90 as a high-speed (for the day) /10
prescaler stage. The biquinary nature of the division was not a
requirement. While I have seen a lot of DIP-8 and SMD prescalers,
they seem to all be either powers of 2 or dual modulus for
synthesisers, and again /10 is not apparent.
I would welcome suggestions for functional replacements. If responses
are along the usual lines of "use a PIC", "start with a fresh slate"
or "give up" the please don't waste my time and yours.