[sdiy] [OT] LS Series (Low Power Schottky Logic)

[ChristianH]

Hi all,

I knew this would happen, one century or another. 

For years I've been wondering why they kept all those 74 series alive.
And it's not that I didn't like the situation - I grew up with 74LS, my
granddad used to use them (um, not quite), never bothered to look at
that "new" stuff like HCT.
And in every classic analog poly synth there's LS, so it _must_ be the
right way to do it... ;-)

I didn't find much on direct replacement on the TI site.
Now, has anybody here more experience then me? Can LS in existing
circuits be replaced by 74HCT or 74AHCT (partially, e.g. replacing a
dead chip)? At a quick glimpse, the data sheet specs look pretty
compatible to me, if not better. How does it look in practice? 

Any comments on how robust the (A)HCTs are? In my experience, the LS
proved to be rather indestructible (well, sort of, at least they don't
die immediately e.g. on shorts between pins).

regards
Christian

P.S.: Is this _the_ Scott Evans who once maintained the Akai List?



On Fri, 11 Jan 2002 14:21:06 -0800 Scott Evans, Gen Mgr wrote:

> FWIW (if anyone still uses this stuff or has legacy parts to replace):
> 
> >From the Texas Instrument web site:
> 
> "ON Semiconductor has recently announced their withdrawal from the LS
> market. They are taking lifetime-buy orders through May of 2002 with a
> final delivery date of November 2002. "
> 
> Texas Instruments offers a cross reference replacement guide for ON
> Semiconductor parts at their web site:
> 
> http://focus.ti.com/pdfs/logic/ti_on_ls_xref.pdf
> 
> Links into the TI-LS page may be found at:
> 
> http://focus.ti.com/docs/logic/logichomepage.jhtml
> 
> Scott