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Related question: Ceramic capacitors: how to read 3-digit markings?

I have some ceramic capacitors with a 2-digit marking. How to read them? Do the colored markings at the top mean anything?

7 capacitors

Image description:

  • Brown ceramic capacitors with 10 written and a black mark at the top
  • Brown ceramic capacitors with 47 written
  • Yellow ceramic capactiors with 1n0 written and a green mark at the top
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  • \$\begingroup\$ duplicate of electronics.stackexchange.com/questions/16636/…? \$\endgroup\$ – vicatcu Aug 11 '11 at 23:19
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    \$\begingroup\$ @vicatcu Not exactly duplicate. That question has been answered perfectly about 3-digit markings, but says nothing about 2-digit markings. So, either that question/answer gets expanded (and this is marked as duplicate), or let's leave that one for 3-digit markings and this one for 2-digit markings. Each solution is fine for me. \$\endgroup\$ – Denilson Sá Maia Aug 11 '11 at 23:31
  • \$\begingroup\$ @vicatcu - despite the similar titles, that question concerns caps marked with letters. \$\endgroup\$ – JustJeff Aug 11 '11 at 23:32
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The brown capacitors have values in picoFarads

eg
47 = 47 picoFarad = 47 pF = 0.000 000 000 047 Farad !
10 = 10 pF

enter image description here

For the yellow and green capacitors with markings of the form

anb

enter image description here

Here n = nanoFarad = nF.

1n0 = 1.0 nF
2n2 = 2.2 nF
6n8 = 6.8 nF

Note that the use of xNx here is (probably) unqiue to capacitors in the nF range - I do not recall seeing eg xPx or xUx markings ever.

However page 70 of this superbVishay ceramic single layer capacitors document suggests you might expect to meet any of eg
p68 = 0.68 pF
n15 = 0.15nF = 150 pF
5p0 = 5 pF etc

The green dot is quite likely to be a voltage rating, but alas I don't know what system it uses. There are several different colour/voltage systems. Typically this sort of capacitor is 50 Volt rated but this is not certain.


More usual nnX 3 digit markings

Most capacitor numerical markings are 3 digit and express the value in pF (pico Farad = 10^-12 Farad) with the last digit being a power of 10 multiplier.

So

223 = 22,000 pF = 22 nF = 0.022 uF = 0.000 000 022 F
106 = 10 000 000 pF = 10 uF
100 = 10 pF and NOT 100 pF etc


Part of a larger tutorial series on capacitors. Deals in colour codes. Does not answer exact question but is useful

This does NOT answer the original question but is useful

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  • \$\begingroup\$ This answer is very useful. I have a bunch of capacitors marked 100 and 10, and now I see they all are the same 10 pF ones. \$\endgroup\$ – Al Kepp Jan 3 '13 at 8:39
  • \$\begingroup\$ The top colour-code of "black" most often denotes a temperature-coefficient (black= NP0) of less-than-plusorminus 30ppm/C. Other colours can denote positive or more often negative temperature coefficients. purple= -750ppm/C. But colours can mean different things too - not entirely universal. \$\endgroup\$ – glen_geek Sep 26 '16 at 14:45
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The yellow green capacitors are Philips brand capacitors introduced in the 1960's. The top markings are: Green: Temperature coefficient -330 ppm/°C. Tolerance -20/+50%. Capacitance value range 1nF to 27nF in E3 value series. Further information can be obtained in Philips Pocketbooks popular in the 1960's thru 1980's and available on Ebay for $10 to $20.

Also the black top marking on the brown ceramic indicates it is an NPO (Negative Positive Zero) Meaning its Temp Co is 0 ppm/°C at room temperature. Thus it is suitable for use in circuits where frequency or timing accuracy versus temperature change is critical, such as RF filters, Audio and RF Oscillators and Digital CMOS Crystal oscillators.

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If they are physically small and have only two digits, I believe this is just the value in picofarads.

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    \$\begingroup\$ 2 digits and nothing else = pF. xNy = x.y nF. \$\endgroup\$ – Russell McMahon Aug 12 '11 at 0:21
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The small ceramic capacitors with 2 digits markings can be identified with their color and the type of markings:

  • Generalizing, The small brown capacitors have written with the value of the capacitance with a multiplier 10^(-12) i.e. picofarad

  • The capacitor with value written as 1n0, 2n2, 47n means :

1n0 = 1.0nF

2n2 = 2.2 nF

47n = 47 nF

and so on.

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