17 Oct
2007
17 Oct
'07
3:24 p.m.
On Tuesday 16 October 2007 13:21, der Mouse wrote:
I just wondered because I'm running into more and more variations on the 74xx
numbers, ones that don't make a whole lot of sense, while adding some
datasheets to the parts pages. And I'm beginning to get the feeling that I'm
reaching the point of diminishing returns with that stuff, that it might not
be worth my while to bother with it.
In addition to those, I ran across 74ASTxxx, 74ACQ (and 74ACTQ, which I'm
guessing is the standard "works with TTL thresholds" variant), 74ALV, 74ALVC,
74ALVCF, 74ALVCH, 74FR, 74LCX, 74LVTH, 74OL, 74VCX, 74VCH (and 74VHCT), and
74VHCU.
And this was all from only one mfr.! (Fairchild, in case anyone's curious.)
The "LV" stuff seems to mean "Low Voltage", and the "Q"
means Quiet (in terms
of glitching or power supply noise or something), I'm not sure about the
rest of it.
I noted that I'd skipped those, and did not bother putting them into the
table with the rest, for now. Somehow I doubt that I'm likely to run into
most of those anyhow...
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
I've just
encountered some datasheets for parts that I've never heard
of before -- 74ABTxxx parts. The lack of a "C" in there would seem
to indicate TTL of some sort but looking at the datasheet the power
supply current would seem to indicate CMOS of some sort, it's in the
uA range.
Anybody ever encountered these before?
I note that packaging seems to be _only_ surface-mount styles.
I think I have some, though I'll have to check when I get home - but
what I have is definitely DIPs, not SMT. If I'm right, ie, if what I
have really is 74ABTxxx, then they're CMOS chips with TTL-compatible
interfaces, ie, you can connect them directly to real 74xxx TTL logic.