morphed to TTL part number history, was: IBM PLAYING CARDS

Tim Shoppa shoppa_classiccmp at trailing-edge.com
Sun Dec 18 10:29:50 CST 2005


Scott Stevens <chenmel at earthlink.net> wrote:
> On Sat, 17 Dec 2005 22:37:49 -0700
> woodelf <bfranchuk at jetnet.ab.ca> wrote:
>
> > I  downloaded some motorola application notes from bitsavers.
> > Wow they sure had a  lot of  different types of  TTL. I wonder
> > how only  the 74xx became the only TTL used today?
> > 
>
> 74xx somehow became the only packing and numbering convention
> used.  There isn't any one single family of 74xx integrated
> circuits.  Manufacturers, for some reason, decided to shove the
> various code letters between numbers for entirely different
> silicon processes, i.e. 74Sxx 74ASxx 74Lxx 74LSxx 74Hxx ...
>
> Has anybody ever tried to compile a list of ALL the various 74xx
> logic gate families, with info about the silicon design/structure
> of each?

Wow, it's pretty hard to meet the demand of "ALL".

The various TTL handbooks from TI/Motorola/National/etc. do a
halfway decent job of describing their silicon processes (not
always identical from manufacturer to manufacturer, even with
the same part numbers) at least at the "why you should use our
brand of chips" level.  Probably very insufficient in terms of
building your own fab line.  Many of these older handbooks
are online at Bitsavers.  These details are conspicuously absent
from most manuals made in the past 15 years or so.

The Motorola TTL and CMOS books from the 70's are particularly good
at giving you a snapshot of the silicon and showing you parasitic
structures in schematics.

The TTL/74x handbooks also do a pretty good job of external electrical
parameters as a function of family, as do Lancaster's TTL cookbook (mid 
70's) and Horowitz&Hill (early 90's so many CMOS parameters too.).  But when
I have to keep up with the 3.3V-and-lower-tiny-fast-bus-driver
74x parts I pretty much have to start from scratch with electrical
parameters, I can't keep them straight anymore.

I suspect that you're asking about enough detail to lay out your
own silicon and start your own fab line, and I don't think I've
ever seen anything that'd teach you how to do that. The EE texts I've
seen on this subject tend to concentrate almost exclusively 
on VLSI and NMOS/CMOS processes.

The 70's-era TTL/Moto/National handbooks do have many transistor-level
diagrams with resistor values (especially for simple gates and some of
the more complex flip-flops), combined with some guesses at transistor
parameters these can be used to build not-so-bad SPICE models, if that's
where you want to go. Sometimes they even include the parasitic
structures in their schematics.

Tim.



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