Can tantalum capacitors be used instead of electrolytic ones?

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#1
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Hi,

 

I am wondering if tantalum capacitors can be used instead electrolytic capacitors for the Vin and Vout of a power source?  My power source is basically the USB power, 5V and 500mA max.

 

Thanks!

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Well it depends how much capacitance you need. Electrolytics generally offer larger capacitance at a lesser price than tantalum's but have a crappy performance. Tantalum's work well in their ranges but can catch on fire (and are more expensive). Since I'm basically just quoting Dave Jones I'd recommend watching this video: https://www.youtube.com/watch?v=...

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Err - Tanatalum capacitors are electrolytic: http://en.wikipedia.org/wiki/Tan...

 

I guess what you mean is, "...if tantalum capacitors can be used instead of aluminium electrolytic capacitors" ?

 

http://en.wikipedia.org/wiki/Alu...

 

And, Yes - tantalum capacitors are commonly used in such applications.

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Do your homework on the USB spec, also.

 

The original USB spec, IIRC, had a maximum 10 uF cap limit on the input from the USB port.

 

There are now several different USB spec's for data, USB charging, etc., and they may have different, (and higher) Cin limits.

 

JC

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You DO NOT want to use tantalum caps on power supply lines that have high current limits. The result CAN BE FIRE.

 

Tantalum caps frequently develop pin-holes in the dielectric, internally. These holes self-repair if the available current is not too high. No, I don't know what "too high" is, but USB tends to be current limited. You do need to pay attention to the maximum capacitance spec on USB supply bus.

 

You generally pay more for tantalum cap having the same capacitance and voltage rating compared to aluminum. What you get for that extra cost is lower ESR and smaller physical size. You also get major limits on maximum voltage rating AND the "breakdown issue" described, above.

 

Jim

Jim Wagner Oregon Research Electronics, Consulting Div. Tangent, OR, USA http://www.orelectronics.net

Last Edited: Mon. Dec 29, 2014 - 04:52 AM
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agree with all comment, if you work with "low voltage" and need small capacitor size, use ceramic. 10uF 0805 , current and cheap. 

ceramic need more DC voltage to give you max value, use 10V or more for 5V supply. ( derating of ceramique value)

http://www.niccomp.com/help/Volt...

 

Thierry

Thierry Pottier

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Ceramic caps have largely obsoleted tantalum caps.

Ceramics over 100 uF with ESR under 100 mΩ are generally available.

Last Edited: Fri. Apr 28, 2017 - 03:24 PM
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trivet - what possessed you to randomly reply to a thread three years old?

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Kartman> what possessed you to randomly reply to a thread three years old?

 

I recently went through the same process.

 

The question and information are still relevant

 

Is there a problem with updating information in the forums?

Last Edited: Fri. Apr 28, 2017 - 03:25 PM
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the state of the art hasn't changed much regarding caps and ldos in three years. The moderators can give you their views on resurecting old threads.