Rated voltage of chip capacitor
The rated voltage of a capacitor refers to the maximum voltage that the capacitor allows for normal operation. However, capacitors exceeding the rated voltage will not necessarily be broken down. The capacitor also has a parameter called breakdown voltage. The breakdown voltage is greater than the rated voltage. If the breakdown voltage is exceeded, the capacitor will be broken down and damaged.
All capacitors have a maximum rated voltage. The higher the rated voltage, the better. When choosing a capacitor, consider the voltage across the capacitor. The data sheet usually gives the maximum amount of voltage applied to the capacitor without damaging the capacitor's dielectric material: operating voltage or DC operating voltage.
If the voltage applied to the capacitor is too large, the dielectric will break down and an arc will be generated between the capacitor plates, resulting in a short circuit. The operating voltage depends on the type of dielectric material used and its thickness.
This is the DC working voltage of a capacitor. For a capacitor with a rated DC voltage of 100 volts, the maximum DC voltage cannot safely withstand an AC voltage of 100 volts. Then, a capacitor that is required to operate at 100 volts AC voltage should have an operating voltage of at least 200 volts. In fact, a capacitor should be selected so that its operating voltage DC or AC is at least 50% greater than the highest effective voltage to be applied.
Another factor that affects the operation of capacitors is dielectric leakage.
Generally, it is assumed that the resistance of the dielectric is extremely high, and a good insulator will prevent direct current from flowing through the capacitor from one plate to the other (as in the l theory). However, if the dielectric material is damaged due to excessive voltage or overheating, the leakage current flowing through the dielectric will become extremely high, resulting in rapid loss of charge on the board and overheating of the capacitor, which will eventually lead to premature failure of the capacitor. Then, never use the capacitor in a circuit with a voltage higher than the capacitor's rating, otherwise it may become hot and explode.
Temperature is an extremely important factor for the operation of capacitors, including ambient temperature and operating temperature. Under normal circumstances, when using chip capacitors, you must not only consider the capacity and withstand voltage of the capacitor, but also consider the impact of temperature on the chip capacitor. In fact, many parameters of the chip capacitor are closely related to temperature. Therefore, when using it, pay attention to whether the temperature has any effect on the capacitor, especially when designing precision circuits and long-life circuits, the relationship between temperature and capacitors should be fully realized.