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regulator output capacitor

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STOIKOV

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I want to use this voltage regulator, its data sheet says the device can accept any output capacitor less than 1µF. Normally output capacitors are ceramic (no polarity) but I got 1µF and 0.68µF tantalim. It's a matter using output capacitors with polarity or not.

**broken link removed**
 

Polarised capacitors will work provided you connect them the right way around.
 

    STOIKOV

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One reason is that ceramic capacitors are cheap, but tantalium capacitors are very expensives the ones more expensives are the teflon capacitors.
 

    STOIKOV

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Besides the price, what is the difference between teflon and tantalium cap?
It is better use in what application?
 

    STOIKOV

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Capacitor type depends on environment and regulator usage. If the regulator you will be using has relatively high output current, you want a larger value capacitor for load regulation. For temperature, tantalums are excellent for their temp range, holding up well for automotive temps, say -40C to +125C. They also exhibit lower ESR for larger values, where the ESR is, roughly, directly inversely proportional to its value. So, a 4.7uF tant has an ESR of about 1ohm, then a 47uF tant has an ESR of about 0.1ohm.

Ceramics are definitely cheap. Very good for filtering.

Electrolytics are good for load regulation as well. They aren't as good for temp range. They freeze out.
 

    STOIKOV

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Info on ESR (equivalent series resistance) can be found at:
https://xtronics.com/reference/esr.htm

In 99.9999999% the value of the output capacitor is not critical, whether you use 1µF or 0.68µF is really not important .. anthing ≥100nF should work ..
Quite often you will find out that there are two capacitors hooked up to the output of a voltage regulator: one ≈10µF electrolitic and one 100nF ceramic (see picture below) ..

Regards,
IanP
 

    STOIKOV

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