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The tolerance value of a capacitor describes the extent to which the actual capacitance can vary from its specified nominal capacitance value. Tolerance is often expressed as a percentage, and may also be expressed as an actual value (i.e., 20pF+-1pF). In general, capacitors should be selected with an understanding of the given application’s sensitivity.
Tolerance values of +-5% and +-10% are ±5%/10%/20% are commonly used for coupling and decoupling applications. More sensitive applications may require the use of capacitors with tolerances of +-1% and +-2% or ±1% and ±2% or better. For example, ceramic capacitors used for coupling and decoupling applications are typically rated at +-5% and +-10%±5% and ±10%, or ±20%. Electrolytic capacitors often have a tolerance of -20% and +80%.
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