Temperature dependent characteristics
Prior to the selection of suitable ratings, consider the factor of the temperature change inside the equipment.
The electrical characteristics of the capacitor changes depending on the temperature.
Factors of the temperature change within the equipment
- (1) Seasonal variation (e.g., winter and summer)
- (2) The temperature changes in a day (e.g., daytime and nighttime)
- (3) The operational status of equipment, i.e. operation mode or standby mode
- (4) Temperature in the capacitor rises effected by the heat conduction or radiant heat from the nearby components.
Influence of operating temperature on electrical characteristics See Below
- (1) At a high temperature ： - Decrease of capacitance
- Increase of ESR at high frequency
- Decrease of insulation resistance
- (2) At a low temperature ： -Decrease of capacitance
- Increase of ESR at low frequency
Since a ceramic capacitor employs ceramic dielectric, whose dielectric constant depends on the temperature,
capacitance of the capacitor may change significantly when the operating temperature range is wide.
The following actions for securing a suitable capacitance are recommended.
- (1) It is recommended to make narrow operation temperature variation by component selection and component position under designing of electronic instrument, in order to minimize the capacitance variation by temperature change.
- (2) The capacitance may change even if the ambient temperature is within the rated temperature.
In addition to the above mentioned concern, the DC voltage characteristic and the capacitance aging of a capacitor should be taken into consideration when selecting a capacitor if the capacitor is to be used for a circuit that needs a narrow capacitance tolerance such as a time constant circuit.
Safety Application Guide for Multilayer Ceramic Chip Capacitors All Lists