Rob van der Putten wrote: > > In V24 it's -25 ... 25 V [1]. -3 ... 3 V isn't defined.
V.24 doesn't specify electrical characteristics. I suspect you mean V.28. RS232 C is also 25 volts, open circuit, although drivers for both standards are not required to be able to achieve this. > [2] TTL high is actually Ca 3.5 V. CMOS high is 5 V (when supplied > with 5 V power). Totem poll TTL high is 2.4V at 400 micro Amps. LS TTL is 2.7V. (National Semiconductors Data Book, 1976) CMOS is 4.95V minimum into infinity, at 5V Vdd, or 4.6 volts at 300 micro amps. The CMOS case corresponds to a load resistance that is a little higher than that of an RS232 C receiver, so one would expect somewhat lower an output voltage into the real load. Figures for 4000 series CMOS, from 1975 RCA COS/MOS Integrated Circuits Data Book. _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
