■Rating
1.Temperature Dependent Characteristics
1. The electrical characteristics of the capacitor can change with temperature.
ꢀ1-1. For capacitors having larger temperature dependency, the capacitance may change with temperature changes.
The following actions are recommended in order to ensure suitable capacitance values.
(1) Select a suitable capacitance for the operating temperature range.
(2) The capacitance may change within the rated temperature.
When you use a high dielectric constant type capacitor in a circuit that needs a tight (narrow) capacitance tolerance (e.g., a time-constant circuit),
please carefully consider the temperature characteristics, and carefully confirm the various characteristics in actual use conditions and the actual system.
[ Example of Temperature Caracteristics X7R(R7) ]
[ Example of Temperature Characteristics X5R(R6) ]
Sample: 0.1μF, Rated Voltage 50VDC
Sample: 22μF, Rated Voltage 4VDC
20
15
10
5
20
15
10
5
0
0
-5
-5
-10
-15
-20
-10
-15
-20
-75
-50
-25
0
25
50
75
100
-75
-50
-25
0
25
50
75
100 125 150
Temperature (ꢀC)
Temperature (ꢀC)
2.Measurement of Capacitance
1. Measure capacitance with the voltage and frequency specified in the product specifications.
1-1. The output voltage of the measuring equipment may decrease occasionally when capacitance is high.
Please confirm whether a prescribed measured voltage is impressed to the capacitor.
1-2. The capacitance values of high dielectric constant type capacitors change depending on the AC voltage applied.
Please consider the AC voltage characteristics when selecting a capacitor to be used in a AC circuit.
3.Applied Voltage
1. Do not apply a voltage to the capacitor that exceeds the rated voltage as called out in the specifications.
ꢀ1-1. Applied voltage between the terminals of a capacitor shall be less than or equal to the rated voltage.
(1) When AC voltage is superimposed on DC voltage, the zero-to-peak voltage shall not exceed the rated DC voltage.
When AC voltage or pulse voltage is applied, the peak-to-peak voltage shall not exceed the rated DC voltage.
(2) Abnormal voltages (surge voltage, static electricity, pulse voltage, etc.) shall not exceed the rated DC voltage.
Typical Voltage Applied to the DC capacitor
DC Voltage
DC Voltage+AC
AC Voltage
Pulse Voltage
0
E
E
E
E
0
0
0
(E：Maximum possible applied voltage.)
1-2. Influence of over voltage
Over voltage that is applied to the capacitor may result in an electrical short circuit caused by the breakdown of the internal dielectric layers.
The time duration until breakdown depends on the applied voltage and the ambient temperature.
GRM1857U1H302JA44-01A
MURATA [ muRata ]
