max232epe gets hot , real hot

[Ioannis]

I would mark the chips, say by a number, and see if the same chip is always the one to heat up. If this is true, then you know what to do...

Ioannis

[richard]

I have tried 5 epe with the same result all are subject to failure to operate ( none have been destroyed yet) and 5 of the 232n variety they never fail . if I leave the sw on and turn the bench supply on/off the chips always work ,if the sw is used to turn the board on then it may or may not work. increasing the ps smoothing cap made things worse . I have tried driving inputs high and low at power up nothing seems to satisfy these beastly chips

[Dave]

I personally would also check the value of the caps I was using as well as the polarity as connected to the MAX-232. I have used these level converters for over 20 years and have never had a problem with them. Although now that I remember, I did have one that did not have an very robust negative supply.

[richard]

I was just looking at a schematic for a microchip usb/serial debugger header and noticed they only use 0.1uF caps on pins 2 and 6 (the +- 10v rails) in lieu of the recommended 1.0uF or bigger by the maxim datasheet. tried that, it has improved the charge pump startup to almost 100% .
fingers crossed

ps the max232n seem to switch the caps @19khz the max232epe @640khz they are quite different animals

[Ioannis]

Seems logical, higher frequency, lower capacity.

I believe this was the problem.

Ioannis