Hi there
David Woolley wrote: > V.24 doesn't specify electrical characteristics. I suspect you mean > V.28. The standard was 'split' at some point (I haven't looked into this stuff for years). > RS232 C is also 25 volts, open circuit, although drivers for both > standards are not required to be able to achieve this. > 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. Regards, Rob _______________________________________________ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
