Date: Wed, 4 Oct 1995 11:08:39 +0200 (EET)
From: Joachim Verghese <jocke@netcontrol.fi>
Cc: analogue@hyperreal.com
Subject: Re: Driver thanks and an ignorant question

On Wed, 4 Oct 1995 PapaJ59871@aol.com wrote:

> And since I among so worldly wise a group, can anyone tell
> me what exactly NPO stands for on a ceramic disk capacitor?

NP0 (N-P-zero) describes the properties of the dielectric material.

NP0 is a Class 1 dielectric, i.e. it has good high frequency behaviour
and stability.

N stands for "negative" temperature coefficient, P for "positive,
and the number is the temp coeff in ppm/deg(C).

Examples:

Dielectric    Temp.Coeff.   Color code    EIA code

P100          +100 +-30     red/violet    M7G
NP0           0    +-30     black         C0G
N075          -75  +-30     red           P2G
N330          -330 +-60     green         S2H


Class 2 capacitors have non-linear temperature, frequency, and voltage
dependencies. Typical Class 2 materials are Z5U and X7R.

Class 3 ceramic caps are semiconductor-based, and have a small physical
size, and low operating voltage.

Hope this helps.

-joachim