In message <[EMAIL PROTECTED]>, John Ackermann N8UR writes: >For what it's worth, the risetime of the MAX232 output is about 2.5us, >in a very smooth ramp -- it's spec'd at 4 v/us. I have heard that the >risetime is deliberately slow to match the RS-232 spec; I don't know >whether that's true. The later version MAX232A is spec'd at 12 v/us; >still not all that speedy.
It's mainly an EMI issue, if the flanks are too steep, kit fails the EC mark test because they're too noisy. Since RS-232 is usually limited to around 110kHz max, there is no need 4uS is a sufficient flank. Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
