Pay attention to the problem of using ceramic capacitors

How to buy high quality ceramic capacitors, teach you some methods, hope to help you. When buying a ceramic capacitor, the first thing to consider is the withstand voltage problem, not the capacity. If the voltage across the chip capacitor exceeds its rated voltage, the product will be broken down, causing failure, and even more fatigue. Components, so it is very important to consider the withstand voltage problem.

The voltage division of the ceramic capacitor is 300V, 400V, 500V, 1KV, 2KV, etc. The breakdown voltage of the ceramic capacitor is 1800V, 4000V, etc., after the pressure problem is solved, the capacity of the product is selected, and the capacity of the ceramic capacitor is Generally, microfacies (uf) are used, such as 1uF=1 microfarad, and most capacitors have a size of about 0.1 to 0.01 μF. 1 microfarad (μF) = 1000 nanofarads (nF) = 1,000,000 picofarads (pF), must have sufficient capacity for use when purchasing.

The next step is the package specification. The package of the ceramic capacitors is bulk, braided, etc., and should be purchased according to the design of the circuit board. If the above three points are all possible, then consider the error and material of the product. The error of the ceramic capacitor has M file (20% error), K file (10% error), J file (100 5th error), etc., the materials are available in X7R, NPO, Y5U, and Y5V.

Capacitors used in the calibration and installation environment shall be used as capacitors within the rated performance range specified by the product sample design.

High temperature (temperature exceeds the maximum use temperature).

Overcurrent (current exceeds the rated ripple current), the applied ripple current exceeds the rated value, the capacitor body will overheat, the capacity will decrease, and the life will be shortened.

Overvoltage (voltage exceeds rated voltage), when the voltage applied to the ceramic capacitor is higher than the rated operating voltage, the leakage current of the capacitor will rise, and its oxygen property will deteriorate in a short period of time until it is damaged.

When a reverse voltage or an alternating voltage is applied, when the direct current aluminum electrolytic capacitor is connected to the circuit in reverse polarity, the capacitor may cause a short circuit of the electronic circuit, and the resulting current may cause damage to the capacitor. If it is possible to apply a positive voltage to the negative lead in the circuit. Use non-polar capacitors.

Used in circuits that repeatedly charge and discharge abruptly, such as for fast charging applications, the service life may be reduced due to a decrease in capacity, a sharp rise in temperature, and the like.

In an environment directly in contact with water, salt water, oil or condensation, an environment full of harmful gases (sulfide), direct sunlight, ozone, ultraviolet light and radioactive materials, vibration and shock conditions exceed the sample and instructions It is forbidden to use capacitors in harsh environments within the specified range.