16 Jan
2008
16 Jan
'08
9:12 p.m.
From: dwight elvey <dkelvey at hotmail.com>
More voltage and it would have used more power. Less
voltage and it would have been too slow. In the DTL days,
unlike today, the major factor in speed was the transistors
them selves and not the interconnect. Today, the interconnect
dominates and the smaller one can make the transistors,
the shorter the interconnects.
I've got a brief Moto app note here from the late 60's that
essentially says that 7400/5400 TTL could be run from Vcc as high as
+7, so long as V(IH) was not allowed to go any higher than +5. The
term "exceptional circumstances" is used, meaning, I suppose, where
better noise immunity or more speed is required.
Since this is contemporary with 5400/7400 SSI, I don't know if it
could be carried over to more recent MSI/LSI TTL circuits.
RTL had a much wider supply range, IIRC.
FWIW,
Chuck
17 Jan
17 Jan
12:03 a.m.
From: cclist at sydex.com
---snip---
RTL had a much wider supply range, IIRC.
FWIW,
Chuck
Hi Chuck
The RTL I played with was quite fussy about voltage.
It wanted 3.6V. 4V or more and it didn'y work.
I made a digal dice ( that I still have someplace )
It used JK's but I forget what I used for an oscillator.
I had it in one of those clear plastic picture cubes and
used mercury switches to detect the roll. A 9V with
something to regulate ( forget what ).
It went through the 9V battery faster than one could
play a game of monopoly so it wasn't much use.
Display was small LEDs.
Dwight
_________________________________________________________________
Watch ?Cause Effect,? a show about real people making a real difference.
http://im.live.com/Messenger/IM/MTV/?source=text_watchcause
6197
days inactive
6198
days old
1 comments
2 participants
participants (2)
-
cclist＠sydex.com -
dkelvey＠hotmail.com