5V and early ICs / was Re: TRADIC

[Roy J. Tellason]

On Saturday 08 December 2007 18:00, Brent Hilpert wrote:
> "Roy J. Tellason" wrote:
> > On Saturday 08 December 2007 02:03, Brent Hilpert wrote:
> > > Another anecdote I ran across a few years ago in the IEEE AotHoC (which
> > > I wish had kept a ref to), was of an IBM engineer working on one of the
> > > first transistorised designs in the mid-50s (ECL IIRC), telling the
> > > story of how he chose 5 Volts for the logic supply.
> >
> > I've wondered often how the various supply voltages I run into get
> > chosen...
> >
> > Care to elaborate on that a bit?
>
> I wish I could, but without the ref ...
> For what I do recall, the suggestion in the article was that this was the
> first use or choice of 5V for the logic supply, although I can't remember
> whether the 5V was a choice of whim from which other design parameters
> followed, or whether the 5V was an engineered outcome.
>
> Even though I found it an interesting anecdote however, there were, or
> would still be (IMHO) a couple of historical links necessary to show that
> there was a causal connection/influence to the 5V supply standard of the
> later DTL & TTL integrated circuit families.
>
> The earliest reference for real ICs I have is a TI product catalog from
> 1965. The first products mentioned are the "NEW! Series 54 TTL"
> (SN5400,5410,5420..5470) (4.5 to 5.5V of course). The commercial 74xx
> versions apparently followed a little later.

Hm,  I had no idea that stuff was around that early on.  My first encounter 
with those parts was around 1970,  and I still have that particular databook,  
which had the standard parts and the H and L variants.

> Five other digital IC families are mentioned:
>   - Series 53 Modified DTL (SN53x) (different from 'standard' DTL) (3 to
> 4V) - Series 51 RCTL (SN51x) (3 to 6V)
>   - Series 51R (severe environment versions of 51)
>   - Minuteman Series DTL (SN337A..) (produced for the Minuteman II missile)
> (+6V & -3V)
>   - Low-power RTL (SN7xx..) (would become one of the 'standard' RTL
> families) (3V)
>
> A Fairchild catalog from 1966 presents standard 900-series DTL and some
> 9000 series TTL with 5V supplies.

I've never heard of most of those,  though I think I do have some mention of 
those 9xx/9xxxx numbers in my parts pages.  I also have some more tech info 
on hand here that I've downloaded but haven't plowed through yet or installed 
into the charts...

> .. and I may be repeating myself on the list, or this may be more
> well-known than I realise, but another somewhat novel point that is
> apparent from the TI catalog is that the "SN" prefix on Texas Instruments
> ICs is short for "Semiconductor Network", an alternative phrase before
> "Integrated Circuit" became the more accepted phrase.

Well *I* never heard about that one before,  and I've wondered for some time 
what the heck it stood for.  :-)

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