[sdiy] Typical ESR of different capacitors

[Simon Brouwer]

  Op 1-9-2010 15:29, Antti Huovilainen schreef:
> Hi
>
> I'm doing a small digital board that uses an LDO for the +5V supply. 
> This requires a capacitor with relatively low ESR and it got me thinking:
>
> What is the range of typical ESR in various types of capacitors?
>
> It's been hard / impossible to find good information online about the 
> topic as manufacturers tend to only list ESR for their low-ESR 
> capacitor models.

That is not my experience. For example, the first cheap 10uF aluminium 
electrolytic I find on the Farnell site has this datasheet: 
http://www.farnell.com/datasheets/14936.pdf

Wrt your question about dissipation factor and ESR, see 
http://wiki.xtronics.com/index.php/Capacitors_and_ESR#Dissipation_Factor

Up to tens of uF, consider a ceramic capacitor. They have very low ESR. 
For higher capacitance, look for low-ESR aluminium.

By the way, check the datasheet of your LDO for requirements on the 
output capacitor. Some LDO's actually need not-so-good ESR on their 
output for stability. See for example 
http://www.farnell.com/datasheets/53851.pdf page 10.

-- 
Vriendelijke groet,
Simon Brouwer.

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