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What kind of caps to use for MAX232 charge pumps

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tellMeDaBasix

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max232 capacitors

What kind of caps to use for MAX232 charge pumps?

I see some people use electrolytic caps and some ceramic caps and both are working reliably at 56kbps without any data loss/corrpution.

So how to decide what type of caps to use?
 

pranam77

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max232 electro capacitor

I have personally used 10Mfd, 1Mfd, and 100Nf capacitors for MAX232 without any difference in the functioning of the same. for standard application choose those values specified in the datasheet. Good luck
 

tellMeDaBasix

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max232 application

Yes! I have uses these values too withotu any problems!

But my question was what type of caps to use (electrolytic, mylar, ceramic, etc); not what values to use :)
 

pranam77

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max232 heating problem

Use 10mfd electrolytic as standared. Tantalum will be still better. Good luck
 

FvM

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usage of capacitors required for max 232

Instead of adding more subjective specifications, I prefer to refer to the Maxim 232 datasheet. It's rather clear in all regards, I think.
The capacitor type used for C1–C4 is not critical for proper operation. The MAX232E and MAX241E require 1µF capacitors, although in all cases capacitors up to 10µF can be used without harm. Ceramic, aluminum-electrolytic, or tantalum capacitors are suggested for the 1µF capacitors.

When using the minimum recommended capacitor values, make sure the capacitance value does not degrade excessively as the operating temperature varies. If in doubt, use capacitors with a larger (e.g., 2x) nominal value. The capacitors’ effective series resistance (ESR), which usually rises at low temperatures, influences the amount of ripple on V+ and V-.

Use larger capacitors (up to 10µF) to reduce the output impedance at V+ and V-. This can be useful when “stealing” power from V+ or from V-.
 

evanzy

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max232 capacitor 1 µf

Hi all,

According to the datasheet, I prefer to use the ceramic caps with 0.1uF or 1uF for MAX232.

Thank you
Evan
 

snafflekid

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why we use capactors near max 232

Electrolytics are going to have higher ESR, which leads to heating and lower efficiency. I would use ceramic for the better high frequency behavior. The differences are probably not critical however.
 

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