A KYOCERA GROUP COMPANY
AVX
Multilayer Ceramic
Leaded Capacitors
NOTICE: Specifications are subject to change without notice. Contact your nearest AVX Sales Office for the latest specifications.
All statements, information and data given herein are believed to be accurate and reliable, but are presented without guarantee,
warranty, or responsibility of any kind, expressed or implied. Statements or suggestions concerning possible use of our products
are made without representation or warranty that any such use is free of patent infringement and are not recommendations to infringe
any patent. The user should not assume that all safety measures are indicated or that other measures may not be required.
Specifications are typical and may not apply to all applications.
Index
The Capacitor
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9
Dielectrics
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-13
Radial Leads
SKYCAPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-19
CERALAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-23
PACKAGING . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24-25
Two-Pin DIPs
DIPGUARD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26-27
Axial Leads
SPINGUARD . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28-32
MINI-CERAMIC CAPACITOR . . . . . . . . . . . . . . . . . 33
CERALAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34-37
PACKAGING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Military
MIL-C-39014
Radial. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39-42
Axial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43-46
2-Pin DIPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47-52
MIL-C-11015
Radial. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53-54
Axial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55-56
MIL-C-20
Radial. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57-58
Axial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59-62
MIL-C-123
Radial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63-64
Axial . . . . . . . . . . . . . . . . .65-66
2-Pin DIPs . . . . . . . . . .67
Marking . . . . . . . .68
Cross-Ref . . . .68
European CECC
Specifications . .69
The Capacitor
GENERAL INFORMATION
A capacitor is a component which is capable
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:
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:
I
ideal
=
C dV
dt
where
I
= Current
C
= Capacitance
dV/dt
= Slope of voltage transition across capacitor
Thus an infinite current would be required to instantly
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:
R
P
C = .224 KA
t
C
= capacitance (picofarads)
K
= dielectric constant (Vacuum = 1)
A
= area in square inches
t
= separation between the plates in inches
(thickness of dielectric)
.224
= conversion constant
(.0884 for metric system in cm)
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
-6
), nano (10
-9
) or pico (10
-12
) farad level.
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:
L
R
S
C
C
= Capacitance
R
s
= Series Resistance
L
= Inductance
R
p
= Parallel Resistance
Reactance –
Since the insulation resistance (R
p
)
is normally very high, the total impedance of a capacitor
is:
Z=
where
R
S
+ (X
C
- X
L
)
2
2
Z
= Total Impedance
R
s
= Series Resistance
X
C
= Capacitive Reactance =
E
=
1
⁄
2
CV
2
1
2
π
fC
X
L
= Inductive Reactance = 2
π
fL
The variation of a capacitor’s impedance with frequency
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°.
E
= energy in joules (watts-sec)
V
= applied voltage
C
= capacitance in farads
2
The Capacitor
I (Ideal)
I (Actual)
Loss
Angle
Phase
Angle
f
IR
s
V
Insulation Resistance –
Insulation Resistance is the resis-
tance measured across the terminals of a capacitor and
consists principally of the parallel resistance R
P
shown in
the equivalent circuit. As capacitance values and hence the
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.
In practice the current leads the voltage by some other
phase angle due to the series resistance R
S
. The comple-
ment of this angle is called the loss angle and:
Power Factor (P.F.) = Cos
f
or Sine
Dissipation Factor (D.F.) = tan
for small values of the tan and sine are essentially equal
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.
CERAMIC CAPACITORS
E.S.R.
C
Dissipation Factor
The DF/PF of a capacitor tells what percent of the
apparent power input will turn to heat in the capacitor.
Dissipation Factor
=
E.S.R.
=
(2
π
fC) (E.S.R.)
X
C
The watts loss are:
Watts loss
=
(2
π
fCV
2
) (D.F.)
Very low values of dissipation factor are expressed as their
reciprocal for convenience. These are called the “Q” or
Quality factor of capacitors.
Multilayer ceramic capacitors are manufactured by mixing
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.
Metal electrodes are deposited onto the green ceramic
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.
Multilayer ceramic capacitors are available in a wide range of
characteristics, Electronic Industries Association (EIA) and
the military have established categories to help divide the
3
单片机
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
