All,

 A Maxim rep once told me, or maybe I read it in some literature
 somewhere that the charge pump is different in the 232A than the
 one in the 232.  They changed resistor values or something, which
 resulted in the samller capacitance needed to generate the necessary
 voltages.  Thus the smaller caps needed.
 BTW, on the 232, I have used 10uF caps with no apparent problems,
 so I imagine there is a range of values that would be compatible.
 I would guess that the recommended values are the minimum needed to
 operate correctly.

                                           Regards,

                                             Jim



On Fri, 30 June 2000, "Don B. Roadman" wrote:

>
> On 30 Jun 2000, at 9:17, Alan B. Pearce wrote:
>
> > Someone recently was making mutterings about possible problems using
> > the ICD at 3V, but the max232 is only spec'd for 5V. Maxim have a 3 to
> > 5.5V replacement chip which is pin compatible to the MAX232, and so
> > should drop into the ICD without any trouble. The only gotcha would
> > seem to be to take care with the capacitor values in the voltage
> > multiplying section of the chip - see the data sheet. The maxim part
> > number is MAX3232E. Maxim web site at http://www.maxim-ic.com
> >
> Yes, and I remember someone who posted that he had talked to a
> microchip guy at a seminar who told him that the max chip was the
> first thing in the ICD to crap out at about 3 volts, so apparently
> they'll run with less than 5V. I ordered my parts from Jamco, who
> dont have the 3232, so I'll end up using a 232, but I noticed that
> they were pin compatible so maybe I can swap them out some
> day. I also dont under stand the caps, they call for 1uF for the 232
> and .1uF for the 232A. One would think there would be a range of
> cap values, perhaps with a tradeoff curve to indicate maybe less
> ouput drive capability or something. They sure seem to have
> minimalist data sheets :)

jim@jpes.com