> On Aug 20, 2015, at 3:40 PM, Eric Smith <space...@gmail.com> wrote:
>
> On Thu, Aug 20, 2015 at 10:54 AM, Paul Koning <paulkon...@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:
> http://www.ti.com/lit/ds/symlink/sn74ls00.pdf
>
> Ioh(max) Iol(max)
> 7400 -0.4 16
> 74LS00 -0.4 8
> 74S00 -1 20
>
> CMOS for comparison:
> http://www.ti.com/lit/ds/symlink/sn74hct00.pdf
> http://www.ti.com/lit/ds/symlink/sn74act00.pdf
>
> Ioh(max) Iol(max)
> 74HCT00 -4 4
> 74ACT00 -24 24
Ok, clearly my memory was faulty. Thanks for the corrections.
paul
