Parameters and classification of capacitors


  1. Capacitance: The fundamental parameter of a capacitor, indicating its ability to store charge. It is measured in Farads (F).
  2. Voltage Rating: The maximum voltage that a capacitor can withstand. Exceeding this voltage may lead to capacitor damage.
  3. Dielectric Constant: Describes the performance of the dielectric material in a capacitor, affecting the capacitance value. Different dielectric materials have different dielectric constants.
  4. Equivalent Series Resistance (ESR): The equivalent resistance in series with a capacitor, affecting its performance in high-frequency applications.
  5. Tolerance: Indicates the deviation between the actual capacitance value and the nominal value. Common tolerance values include ±5%, ±10%, etc.
  6. Leakage Current: The current that flows between the terminals of a capacitor when it is not charged. Important for low-power applications.


  1. Classification by Dielectric Material:
    • Ceramic Capacitors: Use ceramic as the dielectric material, known for small size and a wide range of capacitance values.
    • Electrolytic Capacitors: Utilize materials like aluminum oxide or tantalum oxide as the dielectric, often offering larger capacitance values but requiring attention to polarity.
    • Film Capacitors: Employ materials like polyester, polypropylene, or polyimide as dielectrics, widely used in high-frequency and precision applications.
    • Tantalum Capacitors: Incorporate tantalum metal for electrodes, featuring high energy density and compact size, suitable for high-performance applications.
  2. Classification by Polarity:
    • Polarized Capacitors: Examples include electrolytic capacitors, which have positive and negative terminals and must be connected with the correct polarity.
    • Non-Polarized Capacitors: Examples like ceramic capacitors have no fixed polarity and can be used in both directions.
  3. Classification by Application:
    • Filtering Capacitors: Used to eliminate high-frequency noise and ripples from power sources.
    • Coupling Capacitors: Employed to couple different sections of a circuit, allowing signal transmission.
    • Decoupling Capacitors: Reduce power supply noise and stabilize voltage, often connected to digital and analog circuits.
    • Timing Capacitors: Control signal timing and frequency characteristics, utilized in oscillators and timing circuits.

These parameters and classifications help in selecting the appropriate type of capacitor based on specific application requirements.