Practical Electronics/Finding component information/Capacitors
Ceramic Numbering CodeEdit
Generally, they use an alphanumeric marking system. The number part is the same as for SMT resistors, except that the value represented is in pF. They may also be written out directly, for instance, 2n2 = 2.2 nF. For capacitors the tolerance code is:
Tolerance Code Tolerance A ± 0.05 pF B ± 0.1 pF C ± 0.25 pF D ± 0.5 pF E ± 0.5% F ± 1% G ± 2% H ± 3% J ± 5% K ± 10% L* ± 15% M ± 20% N* ± 30% P* −0% +100% S* −20% +50% W* −0% +200% X* −20% +40% Z −20% +80%
letters with * are not used consistently.
how similar is this to resistors?
For example, .047K = .047 µF 10%.
The dielectric material is sometimes designated by another code: (note: the materials in the table below are not ceramic capacitors as implied, but plastic and paper)
Marking Material KT Polyester Film / Foil MKT Metallized Polyester (PETP) KC Polycarbonate Film / Foil MKC Metallized Polycarbonate KS Polystyrene Film / Foil KPS foil/pps? MPS Metallized pps KP Polypropylene Film / Foil MKP Metallized Polypropylene MP Metallized paper
Please note that the table above is valid most of the time but not always because it is not a real standard. To be real sure you may check the data sheet from the manufacturer in mind.
The cap color can also indicate the dielectric:
more info at http://my.execpc.com/~endlr/markings.html
Axial ceramic capacitorsEdit
These often have a yellow body, and use the same color band system as resistors, except that the value indicated is in pF.
Multilayer Ceramic capacitorsEdit
These usually use the same alphanumeric system.