TAP/TEP Technical Summary and
Application Guidelines
SECTION 1:
ELECTRICAL CHARACTERISTICS AND EXPLANATION OF TERMS
1.1 CAPACITANCE
1.1.1 Rated capacitance (CR)
1.1.3 Capacitance tolerance
This is the nominal rated capacitance. For tantalum capaci-
tors it is measured as the capacitance of the equivalent
series circuit at 20°C in a measuring bridge supplied by a
120 Hz source free of harmonics with 2.2V DC bias max.
This is the permissible variation of the actual value of the
capacitance from the rated value.
1.1.4 Frequency dependence of the capacitance
The effective capacitance decreases as frequency increases.
Beyond 100 kHz the capacitance continues to drop until res-
onance is reached (typically between 0.5-5 MHz depending
on the rating). Beyond this the device becomes inductive.
1.1.2 Temperature dependence on the capacitance
The capacitance of a tantalum capacitor varies with temper-
ature. This variation itself is dependent to a small extent on
the rated voltage and capacitor size. See graph below for
typical capacitance changes with temperature.
Typical Curve Capacitance vs. Frequency
Typical Capacitance vs. Temperature
1.4
15
10
5
1.2
1.0
1.0F 35V
0
0.8
-5
0.6
0.4
-10
-15
100kHz
1kHz
100Hz
10kHz
Frequency
-55
-25
0
25
50
75
100
125
Temperature (°C)
1.2 VOLTAGE
1.2.1 Rated DC voltage (VR)
Category Voltage vs. Temperature
This is the rated DC voltage for continuous operation up to
+85°C.
100
1.2.2 Category voltage (VC)
90
80
70
60
50
This is the maximum voltage that may be applied continu-
ously to a capacitor. It is equal to the rated voltage up to
+85°C, beyond which it is subject to a linear derating, to 2/3
VR at 125°C.
1.2.3 Surge voltage (VS)
This is the highest voltage that may be applied to a capaci-
tor for short periods of time. The surge voltage may be
applied up to 10 times in an hour for periods of up to
30 seconds at a time. The surge voltage must not be used
as a parameter in the design of circuits in which, in the
normal course of operation, the capacitor is periodically
charged and discharged.
75
85
125
95
105
115
Temperature °C
150 ■ MAY 2013