How do I know if a Capacitor is Low ESR

koossa · Joined: 16 Oct 2005 Posts: 1

Good day

I have asked for low ESR Electrolytic Capacitors, and they gave me the following 3 types :
http://www.hitano.com.tw/PDF/EXR.pdf
http://www.hitano.com.tw/PDF/E5R.pdf
http://www.hitano.com.tw/PDF/EHR.pdf

How do I know if they are low esr?

Ry · Guest

ESR is rather complex & dependent on several different factors (ie voltage, operating freq, construction..etc) and may not be readily listed. However as a rule of thumb it is directly related to "dissipation factor" which by itself is variable.

Therefore in general terms, the higher dissipation factor means higher ESR.
but again, it is still very much dependent on your design/application needs.

Technically speaking, ESR of a cap can be calculated by

ESR = Dissipation factor x (2 x TT x f x C) to the -1 factor
f is operating frequency

Guest · Posted: Thu Oct 27, 2005 9:43 am Post subject:

E5R are short capacitors (5mm high) for use in small devices. (Pg 18,)
EHR are high temperature longlife capacitors. (pg 16, 17)
EXR are low impedance and long life. They are also the only datasheet that lists the impedance at 100KHz. They are for switching power supplies and other high frequency applications. Sometimes they are brown in colour. (Pg 23, 24, 25, 26)
This info was taken from the data sheets you posted. (except colour)
Low ESR = low impedance.

Let us know if this is of any help. Very Happy