Newsgroups: sci.electronics
Path: utzoo!henry
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: What's the fastest TTL-compatible XOR gate available commercially ?
Message-ID: <1991Apr11.154024.28033@zoo.toronto.edu>
Date: Thu, 11 Apr 1991 15:40:24 GMT
References: <40750@netnews.upenn.edu> <7380022@hpnmdla.hp.com>
Organization: U of Toronto Zoology

In article <7380022@hpnmdla.hp.com> roger@hpnmdla.hp.com (Roger Petersen) writes:
>You could check out the 74AS86.  AS is typically slightly faster
>than F (but you have to deal with the faster edge rates too).
>My latest AS databook only shows typical prop. delays, no worst case,
>so I don't know how fast they really are.

The standard rule of thumb for TTL -- although applicability to AS is a
little unclear -- is that worst case over full range is twice typical.
(Beware:  the "max" numbers on old TTL data sheets are at 5.0000V and
25.0000degC, not over the full range.)  That gives AS no advantage over
F in this case.
-- 
And the bean-counter replied,           | Henry Spencer @ U of Toronto Zoology
"beans are more important".             |  henry@zoo.toronto.edu  utzoo!henry