Key Points for Selecting Ceramic Chip Capacitors (MLCC) 1

(1) Capacity and Tolerance: The permissible deviation range between the actual capacitance and the nominal capacitance. Commonly used tolerance levels include: Class J ±5%, Class K ±10%, Class M ±20%

Precision capacitors have smaller allowable tolerances, while electrolytic capacitors have larger tolerances, and they employ different tolerance classes  diode

The precision grades of commonly used capacitors are represented in the same manner as resistors. The letter designations are as follows: Class—±0.5%; F Class—±1%; G Class—±2%; J Class—±5%; K Class—±10%; M Class—±20%

(2) Rated working voltage: The maximum DC voltage that a capacitor can withstand and operate stably and reliably in a circuit for the long term, also known as the voltage endurance. For components with the same structure, dielectric material, and capacitance, higher voltage endurance results in a larger volumediode

(3) Temperature coefficient: The relative change in capacitance per 1°C temperature variation within a specified temperature range. The smaller the temperature coefficient, the better

(4) Insulation resistance: Indicates the magnitude of leakage current. Generally, capacitors with small capacitance have very high insulation resistance, ranging from hundreds of megohms to several thousand megohms. Electrolytic capacitors typically have lower insulation resistance. In general, the higher the insulation resistance, the better, as it results in less leakage current

(5) Loss: Under the influence of an electric field, the energy consumed by a capacitor as heat per unit time. These losses primarily originate from dielectric loss and metal loss. They are typically represented by the tangent of the loss angle

(6) Frequency characteristics: The property of capacitors where their electrical parameters vary with the frequency of the electric field. For capacitors operating under high-frequency conditions, the permittivity is smaller at high frequencies than at low frequencies, resulting in a corresponding decrease in capacitance. Additionally, losses increase with rising frequency. Furthermore, when functioning at high frequencies, distributed parameters of capacitors—such as plate resistance, resistance between leads and plates, self-inductance of plates, lead inductance, and others—can all affect capacitor performance. These factors collectively impose limitations on the usable frequency range of capacitorsdiode

Different types of capacitors have varying maximum operating frequencies. Small mica capacitors operate within 250MHz; disc-type ceramic capacitors reach 300MHz; tubular ceramic capacitors are limited to 200MHz; disc-type ceramic capacitors can achieve up to 3000MHz; small paper capacitors are suitable for 80MHz; while medium-sized paper capacitors are only rated for 8MHzdiode