RS-232 Tx / Rx monitoring LEDs?
spacewar at gmail.com
Thu Aug 20 14:40:28 CDT 2015
On Thu, Aug 20, 2015 at 10:54 AM, Paul Koning <paulkoning at comcast.net> wrote:
> Ok, but when you refer to "drive strength" I assumed you were talking about current, not voltage. By that measure totem pole outputs are pretty much symmetrical.
Not for true (bipolar) TTL. See the specs for the 7400, 74LS00, 74S00:
7400 -0.4 16
74LS00 -0.4 8
74S00 -1 20
CMOS for comparison:
74HCT00 -4 4
74ACT00 -24 24
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