SOLID TANTALUM CHIP CAPACITORS
TANTALUM MnO
2
COMPONENT PERFORMANCE CHARACTERISTICS
(con’t.)
20.0
10.0
Multiplier of 120 Hz D.F.
10.0
Multiplier of DC Leakage Current
5.0
Reference 1.0
at + 25°C
Reference
1.0 at 120 Hz
1.0
1.0
100
1k
10k
Frequency — Hertz
FIGURE 6 Typical Effect of Frequency upon Dissipation
Factor
0.1
-60 -40 -20
0
+20 +40 +60 +80 +100 +125
Operating Temperature— C
FIGURE 4
Typical Effect of Temperature upon
DC Leakage Current
DC leakage current decreases with decreasing
applied voltage.
1.0
Multiplier of DC Leakage Current
0.1
Dissipation factor is a very useful low frequency
(120 Hz) measurement of the resistive component
of a capacitor. It is the ratio of the equivalent series
resistance (ESR) to the capacitive reactance, (X
C
)
and is usually expressed as a percentage. It is
directly proportional to both capacitance and fre-
quency. Dissipation factor loses its importance at
higher frequencies, (above about 1 kHz), where
impedance (Z) and equivalent series resistance
(ESR) are the normal parameters of concern.
DF = R = 2 fCR DF = Dissipation Factor
X
C
R = Equivalent Series
Resistance (Ohms)
X
C
= Capacitive Reactance
(Ohms)
f = Frequency (Hertz)
C = Series Capacitance
(Farads)
DF is also referred to as tan or “loss tangent.”
The “Quality Factor,” “Q,” is the reciprocal of DF.
DF decreases with temperature above +25°C and
may also increase at lower temperatures.
Unfortunately, one general limit for DF cannot be
specified for all capacitance/voltage combinations,
nor can response to temperature be simply stated.
DC bias is not commonly used at room tempera-
ture, but is more commonly used at elevated tem-
peratures.
10. Equivalent Series Resistance (ESR) and
Impedance (Z)
Equivalent Series Resistance (ESR) is the pre-
ferred high-frequency statement of the resistance
unavoidably appearing in these capacitors. ESR
is not a pure resistance, and it decreases with
increasing frequency.
Total impedance of the capacitor is the vector
sum of capacitive reactance (X
C
) and ESR, below
resonance; above resonance total impedance is
the vector sum of inductive reactance (X
L
) and
ESR.
7
0.01
0.001
0
10
20
30
40
50
60
70
80
90
100
110
Percentage of Rated Voltage
FIGURE 5
Typical Effect of Applied Voltage on DC
Leakage Current.
9. Dissipation Factor (DF)
Refer to part number tables for maximum DF
limits.
Dissipation factor is measured at 120 Hz, up to
1.0 volt rms maximum, and up to 2.0 volts DC
maximum at +25°C. The application of DC bias
causes a small reduction in DF, about 0.2% when
full rated voltage is applied. DF increases with
increasing frequency.
©KEMET Electronics Corporation, P.O. Box 5928, Greenville, S.C. 29606, (864) 963-6300
Solid Tantalum Surface Mount
KEMET [ KEMET CORPORATION ]
