At 04:54 PM 6/23/2004 +1200, Richard Prosser wrote:

>Peter,
>1k might be a bit high given a "typical" RS232 load. Ferrite beads are more appropriate but a 47 or 100ohm resistor should be OK. The cap could got to 10nF or so (with the 100ohms) , depending on the bit rate but 1nF would be a reasonable starting point.  If you add too much capacitance you can get caught by the series resonance of the cap itself.
>RP

Definitely beads for the high frequency emissions.

One reason I've avoided max chips, is that it's hard to get rid of residual noise from the charge pumps. That frequency range is hard to filter without large components, and affecting the output at 115200 bps.

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