Newsgroups: sci.electronics
Path: utzoo!henry
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: Crossing a 74LS165 to an SK device
Message-ID: <1991Mar5.232429.5485@zoo.toronto.edu>
Organization: U of Toronto Zoology
References: <1991Mar3.221144.6692@uncecs.edu>
Date: Tue, 5 Mar 1991 23:24:29 GMT

In article <1991Mar3.221144.6692@uncecs.edu> crisp@uncecs.edu (Russ Crisp) writes:
>... I found two devices, a SK7C165, and a SK7CT165
>that appear to be the same thing, as far as I can tell.  Anyone
>know if either one of these devices would be a satisfactory
>replacement for a 74LS165?  What is the difference between a
>'C' device and a 'CT' device?  ...

Unfortunately, the answer to the first question is "it depends".  It sounds
like the SK7C165 is what would normally be called a [74]HC165, and similarly
for the CT.  They are all pin-compatible, but the HC165 is CMOS, while the
HCT165 is CMOS with voltage levels fiddled to be more TTL-compatible.  These
parts are rather similar to the LS165, and the CT one might be worth a try,
but both speed and drive characteristics differ enough that a designer
would substitute one for the other only after careful consideration.
-- 
"But this *is* the simplified version   | Henry Spencer @ U of Toronto Zoology
for the general public."     -S. Harris |  henry@zoo.toronto.edu  utzoo!henry