On Sun, 19 Jan 2003, M H Stein wrote:
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One question. Assuming the signal names are conventional, that's the same
pinout as the '154 decoder. And yet my (ancient, hardbacked) TI TTL book
says that while the 74154 is a logical replacement, it's not a direct
replacement (this implies to me a different pinout). One of the pinouts I
received had the A inputs in the oposite order (20 = A0 .. 23 = A3). Can
somebody please check which is correct.
-tony
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Well, you'll probably get another dozen replies from the other helpful folks
here, but the pinouts and logic tables are identical and 23=a0, 20=a3.
I thought the same when I looked at the 9311, that it sure looked like a
74154 which was used everywhere, and that there must be a pinout or
big characteristic difference to make it worth FSC's while (since they
also made the '154, and TI, NSC and Motorola, who also made the 9311).
Didn't the 9311 pre-date the 74154? IICRC, a lot of the the 9300
series stuff got copied by TI (9300,9316 for example) when they got the
synchronous is better message that Fairchild was promoting with the 9300
series... (wish I still had that Orange 9300 series designers guide)
But the only difference I can see is that the max propagation delay is
less on the 9311; maybe someone else will see something else.
mike
Peter Wallace
Mesa Electronics