Function of IC MAX 232

[faiza nasir]

i have two questions to ask about MAX 232.

1) in IC MAX 232,what is the purpose of combining the pin no (1 and 3) and pin (4 and 5) through capacitor of 1uF.

2)according to the data sheet of the IC the capacitor of 1uF attached to pin 2 could either be grounded or could be attached to Vcc.why?

plz explain it properly.i have no idea why is this so.

 

[andre_luis]

Those capacitors are required to perform voltage multiplier circuit based on "switched diode" approach.
Once is very expensive to build capacitors on silicon wafer, such pins allow user to do that externally to the chip.


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[crutschow]

The answer to 2) is that the capacitor must be connected to AC ground. Both the common line and the Vcc line are considered AC ground.