How Do I Choose the Correct Ceramic Capacitor?
The correct capacitor choice depends on the intended use of the component, such as whether it is installed within a device's power supply or is part of a bypass circuit. Ceramic capacitors are categorized into three classes; these classes vary in component quality and function. Class three is best for power supplies, class two for bypass circuits, and class one for sensitive circuits. In addition, a ceramic capacitor can vary in shape, from a small surface mounted component to a large soldered part.
You can choose a ceramic capacitor in the class three category for power supply applications. Class three components are not meant for high accuracy applications; these capacitors can change in their capacitance value over time, which alters the amount of electricity running through a circuit. These components work well in power supplies since they are lower in cost; power supplies require many capacitors for proper circuit functioning.
A class two ceramic capacitor offers more electrical efficiency through the component's many layers. These capacitor types work well in bypass circuits; however, they still suffer from poor accuracy. Similar to the class three category, the capacitance varies greatly as the component warms up. You should keep in mind that these components are not meant for sensitive electrical circuits.
Class one capacitors offer the best accuracy of all the categories. The component can withstand temperature changes without altering the electrical flow through the circuit. You can choose this ceramic capacitor for sensitive circuits, such as for a computer motherboard. The high quality capacitor design will cost more than the other two categories; you should consider this factor when choosing the correct component.
Each one of the capacitor classes offers two functional shapes, either surface mounted or hole soldered. Capacitors that are surface mounted are typically very small; these components may require special tools for installation and removal. Many times, these capacitors are mounted by computers and automated machines since they can be extremely small.
Hole soldered capacitors are the most common component design. These capacitors have wire legs that are installed within printed circuit board holes and soldered for a proper connection. Hobbyists may use this type of capacitor design since it is easier to handle during installation and removal; soldering tools are less expensive and easily available at local electronics stores.
Before choosing a ceramic capacitor, you should verify the specific capacitance value needed for the particular circuit. Each capacitor has a value printed on its outside shell; most circuits have schematics that provide the needed value. You can match the schematic value with the printed number on the capacitor to ensure a proper component choice.
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