voltage doubling in max 232

[qtommer]

the voltage doubling of a the max232 as shown in the datasheets suppose to reach +10V/-10V. However, in practical only +8V/-8V are achieved using the specified cap values. Is there any reason why this happens? thanks

 

[crutschow]

The TI Max232 datasheet shows a typical output of ±7V and a minimum of ±5V. Why do you think it should output 10V?

 

[ericgibbs]

the voltage doubling of a the max232 as shown in the datasheets suppose to reach +10V/-10V. However, in practical only +8V/-8V are achieved using the specified cap values. Is there any reason why this happens? thanks

The highest I have seen on a MAX232 is +/-9V.

 

[qtommer]

thanks you all for replying

its because according to the MAXIM datasheet, in the MAX232 schematic, the caps are connected to a section called a voltage doubler (+10V) and voltage inverter (-10V) .

Why is 1uF chosen as the cap value? is it due to the fact that it provides a maximum 5V charge ? if so how can i deduce the value? thanks