**The Capacitor**

**. . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9**

**Dielectrics**

**. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-13**

**Radial Leads**

**SKYCAPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-19**

CERALAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-23

PACKAGING . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24-25

CERALAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-23

PACKAGING . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24-25

**Two-Pin DIPs**

**DIPGUARD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26-27**

**Axial Leads**

**SPINGUARD . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28-32**

MINI-CERAMIC CAPACITOR . . . . . . . . . . . . . . . . . 33

MINI-CERAMIC CAPACITOR . . . . . . . . . . . . . . . . . 33

**CERALAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34-37**

**PACKAGING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38**

**Military**

**MIL-C-39014**

**Radial. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39-42**

Axial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43-46

2-Pin DIPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47-52

Axial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43-46

2-Pin DIPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47-52

**MIL-C-11015**

**Radial. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53-54**

Axial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55-56

Axial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55-56

**MIL-C-20**

**Radial. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57-58**

Axial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59-62

Axial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59-62

**MIL-C-123**

**Radial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63-64**

**Axial . . . . . . . . . . . . . . . . .65-66**

2-Pin DIPs . . . . . . . . . .67

Marking . . . . . . . .68

Cross-Ref . . . .68

2-Pin DIPs . . . . . . . . . .67

Marking . . . . . . . .68

Cross-Ref . . . .68

**European CECC**

**Specifications . . 69**

**Index**

**GENERAL INFORMATION**of storing electrical energy. It consists of two conductive

plates (electrodes) separated by insulating material which is

called the dielectric. A typical formula for determining

capacitance is:

**C =**

**.224 KA**

**t**

**C**= capacitance (picofarads)

**K**= dielectric constant (Vacuum = 1)

**A**= area in square inches

**t**= separation between the plates in inches

**.224**= conversion constant

**Capacitance **The standard unit of capacitance

is the farad. A capacitor has a capacitance of 1 farad

when 1 coulomb charges it to 1 volt. One farad is a very

large unit and most capacitors have values in the micro

(10

**Dielectric Constant **In the formula for capacitance

given above the dielectric constant of a vacuum is

arbitrarily chosen as the number 1. Dielectric constants

of other materials are then compared to the dielectric

constant of a vacuum.

**Dielectric Thickness **Capacitance is indirectly propor-

tional to the separation between electrodes. Lower volt-

age requirements mean thinner dielectrics and greater

capacitance per volume.

**Area **Capacitance is directly proportional to the area of

the electrodes. Since the other variables in the equation

are usually set by the performance desired, area is the

easiest parameter to modify to obtain a specific capaci-

tance within a material group.

**Energy Stored **The energy which can be stored in a

capacitor is given by the formula:

**E**=

**1**

**/**

**2**

**CV**

**2**

**E**= energy in joules (watts-sec)

**V**= applied voltage

**C**= capacitance in farads

**Potential Change **A capacitor is a reactive

component which reacts against a change in potential

across it. This is shown by the equation for the linear

charge of a capacitor:

**C**

**dV**

**dt**

**I**= Current

**C**= Capacitance

**dV/dt**= Slope of voltage transition across capacitor

change the potential across a capacitor. The amount of

current a capacitor can "sink" is determined by the

above equation.

**Equivalent Circuit **A capacitor, as a practical device,

exhibits not only capacitance but also resistance and

inductance. A simplified schematic for the equivalent

circuit is:

**C**= Capacitance

**L**= Inductance

**R**

**s**

**R**

**p**

**Reactance **Since the insulation resistance (R

is:

**Z**= Total Impedance

**R**

**s**

**X**

**C**

**X**

**L**

determines its effectiveness in many applications.

**Phase Angle **Power Factor and Dissipation Factor are

often confused since they are both measures of the loss

in a capacitor under AC application and are often almost

identical in value. In a "perfect" capacitor the current in

the capacitor will lead the voltage by 90°.

**The Capacitor**

**R**

**L**

**R**

**C**

**P**

**S**

phase angle due to the series resistance R

which has led to the common interchangeability of the two

terms in the industry.

**Equivalent Series Resistance **The term E.S.R. or

Equivalent Series Resistance combines all losses both

series and parallel in a capacitor at a given frequency so

that the equivalent circuit is reduced to a simple R-C series

connection.

**Dissipation Factor**

apparent power input will turn to heat in the capacitor.

**Dissipation Factor**=

**E.S.R.**

**(2**

**fC) (E.S.R.)**

**X**

**C**

**Watts loss**=

**(2**

**fCV**

**2**

**) (D.F.)**

reciprocal for convenience. These are called the "Q" or

Quality factor of capacitors.

**Insulation Resistance **Insulation Resistance is the resis-

tance measured across the terminals of a capacitor and

consists principally of the parallel resistance R

area of dielectric increases, the I.R. decreases and hence

the product (C x IR or RC) is often specified in ohm farads

or more commonly megohm microfarads. Leakage current

is determined by dividing the rated voltage by IR (Ohm's

Law).

**Dielectric Strength **Dielectric Strength is an expression

of the ability of a material to withstand an electrical stress.

Although dielectric strength is ordinarily expressed in volts,

it is actually dependent on the thickness of the dielectric

and thus is also more generically a function of volts/mil.

**Dielectric Absorption **A capacitor does not discharge

instantaneously upon application of a short circuit, but

drains gradually after the capacitance proper has been dis-

charged. It is common practice to measure the dielectric

absorption by determining the "reappearing voltage" which

appears across a capacitor at some point in time after it

has been fully discharged under short circuit conditions.

**Corona **Corona is the ionization of air or other vapors

which causes them to conduct current. It is especially

prevalent in high voltage units but can occur with low

voltages as well where high voltage gradients occur. The

energy discharged degrades the performance of the

capacitor and can in time cause catastrophic failures.

**CERAMIC CAPACITORS**the ceramic powder in an organic binder (slurry) and cast-

ing it by one technique or another into thin layers typically

ranging from about 3 mils in thickness down to 1 mil or

thinner.

layers which are then stacked to form a laminated

structure. The metal electrodes are arranged so that their

terminations alternate from one edge of the capacitor to

another. Upon sintering at high temperature the part

becomes a monolithic block which can provide extremely

high capacitance values in small mechanical volumes.

Figure 1 shows a pictorial view of a multilayer ceramic

capacitor.

characteristics, Electronic Industries Association (EIA) and

the military have established categories to help divide the

**The Capacitor**

**E.S.R.**

**C**

Angle

Angle

**The Capacitor**

basic industry specification for ceramic capacitors is EIA

specification RS-198 and as noted in the general section

it specifies temperature compensating capacitors as Class

1 capacitors. These are specified by the military under

specification MIL-C-20. General purpose capacitors with

non-linear temperature coefficients are called Class 2

capacitors by EIA and are specified by the military under

MIL-C-11015 and MIL-C-39014. The new high reliability

military specification, MIL-C-123 covers both Class 1 and

Class 2 dielectrics.

**Class 1 **Class 1 capacitors or temperature compensating

capacitors are usually made from mixtures of titanates

where barium titanate is normally not a major part of the

mix. They have predictable temperature coefficients and

in general, do not have an aging characteristic. Thus they

are the most stable capacitor available. Normally the

T.C.s of Class 1 temperature compensating capacitors are

C0G (NP0) (negative-positive 0 ppm/°C). Class 1 extended

temperature compensating capacitors are also manufac-

tured in T.C.s from P100 through N2200.

**Class 2 **General purpose ceramic capacitors are called

Class 2 capacitors and have become extremely popular

because of the high capacitance values available in very

small size. Class 2 capacitors are "ferro electric" and vary in

capacitance value under the influence of the environmental

and electrical operating conditions. Class 2 capacitors

are affected by temperature, voltage (both AC and DC),

frequency and time. Temperature effects for Class 2

ceramic capacitors are exhibited as non-linear capacitance

changes with temperature.

**TC TOLERANCES**

**(1)**

stray capacitance.

**Table 1: EIA Temperature Compensating Ceramic Capacitor Codes**

**Figure 1**