
KEMET Electronics Corporation, P.O. Box 5928, Greenville, S.C. 29606, (864) 963-6300
CERAMIC CHIP CAPACITORS
5.
Dissipation Factor:
Measured under same conditions as
capacitance. (See Table 3)
Dissipation factor (DF) is a measure of the losses in
a capacitor under AC application. It is the ratio of the
equivalent series resistance to the capacitive reac-
tance, and is usually expressed in percent. It is normal-
ly measured simultaneously with capacitance, and
under the same conditions. The vector diagram below
illustrates the relationship between DF, ESR and
impedance. The reciprocal of the dissipation factor is
called the
“
Q
”
or quality factor. For convenience, the
“
Q
”
factor is often used for very low values of dissipa-
tion factor especially when measured at high frequen-
cies. DF is sometimes called the
“
loss tangent
”
or
“
tan-
gent
”
, as shown in Figure 2.
6.
Impedance:
Since the parallel resistance (IR) is normally very
high, the total impedance of the capacitor can be
approximated by:
Figure 3
The variation of a capacitor's impedance with fre-
quency determines its effectiveness in many applica-
tions. At high frequency more detailed models apply -
see KEMET SPICE models for such instances.
7.
Insulation Resistance:
Measured after 2 minutes electrification at 25°C and
rated voltage: Limits per Table 3.
Insulation Resistance is the measure of a capacitor
to resist the flow of DC leakage current. It is sometimes
referred to as
“
leakage resistance
”
. Insulation resis-
tance (IR) is the DC resistance measured across the
terminals of a capacitor, represented by the parallel
resistance (IR) shown in Figure 1. For a given dielectric
type, electrode area increases with capacitance, result-
ing in a decrease in the insulation resistance.
Consequently, insulation resistance limits are usually
specified as the
“
RC
”
(IR x C) product, in terms of ohm-
farads or megohm-micro-farads. The insulation resis-
tance for a specific capacitance value is determined by
dividing this product by the capacitance. However, as
the nominal capacitance values become small, the
insulation resistance calculated from the RC product
reaches values which are impractical. Consequently, IR
specifications usually include both a minimum RC prod-
uct and a maximum limit based on the IR calculated
Figure 1
C = Capacitance
IR
ESR
C
ESL
ESL = Equivalent Series Inductance
IR = Insulation Resistance
ESR = Equivalent Series Resistance
ESR x 100
Xc
DF(%) =
Xc
2 π
fC
1
=
Figure 2
δ
Ζ
O
Xc
ESR
Z =
ESR + (XL - XC)
2
Where :
Z = Total Impedance
ESR = Equivalent Series Resistance
XC = Capacitive Reactance = 1/(2
π
fC)
XL = Inductive Reactance = (2
π
f
)
(ESL)
Table 3
–
Specified Electrical Limits
Parameter
Temperature Characteristics
X7R/X5R
C0G
Z5U
Capacitance & Dissipation Factor: Measured at following
conditions:
C0G – 1kHz and 1 vrms if capacitance >1000 pF
1MHz and 1 vrms if capacitance
≤
1000 pF
X7R/X5R/Y5V – 1kHz and 1 vrms* if capacitance
≤
10
μ
F
X7R/X5R/Y5V – 120Hz and 0.5 vrms if capacitance
>
10
μ
F
Y5V
Z5U – 1kHz and 0.5 vrms
DF Limits:
**X5R
<25V
<25V
50 - 200 volts –
25 volts –
16 volts –
6.3/10 volts –
Dielectric Strength: At 2.5 times rated DC voltage
Insulation Resistance (IR): At rated DC voltage, whichever
of the two is smaller. To get IR limit, divide M
F
value by
the capacitance and compare to G
limit. Select the lower
of the two limits.
Temperature: Range,
°
C
Capacitance Change (without DC voltage)
0.10%
0.10%
--------
--------
2.5%
3.5%
3.5%
5.0%
2.5%
5.0%
**
**
Pass Subsequent IR Test
1,000 M
–
μ
F
or 100 G
(100,000 M
)
1,000 M
–
μ
F
or 100 G
(100,000 M
)
100 M
–
μ
F
or 10 G
(10,000 M
)
-55 to +125
0
±
30 ppm/
°
C
-55 to +125
±
15%
-55 to +85
±
15%
+10 to +85
+22% -56%
5.0%
7.0%
7.0%
10.0%
100 M
–
μ
F
or 10 G (
≥
16 volt)
50 M
–
F
or 10G (
≤
10v)
(10,000 M
)
-30 to +85
+22% -82%
4.0%
4.0%
-------
X7R:
X5R:
Cap
<564
≥
564
DF
5.0%
10.0%
*Note: Some values measured at
1
2
volt, see X7R Table for specific details on pages 7
4
and 7
5
.
6
8