pikofarad

Pikofarad (often spelled picofarad; symbol pF) is the SI unit of electrical capacitance equal to 10^-12 farads. The prefix pico- denotes one trillionth, so 1 pikofarad equals 1 × 10^-12 farads. The farad is named after Michael Faraday. In English usage the standard spelling is picofarad, with the abbreviation pF; pikofarad is a less common variant found in some languages or informal contexts.

In practice, pikofarads are used to express very small capacitances found in high-frequency electronics and precision components. They are typical for surface-mount capacitors, RF tuning networks, and decoupling applications where small capacitance values are needed. For reference, 1 pikofarad equals 0.001 nanofarads or 0.000001 microfarads (1 pF = 0.001 nF = 0.000001 µF).

Capacitance values in the pF range are influenced by parasitic effects such as stray capacitance from wiring, pcb traces, and nearby components, which can be significant at high frequencies. The energy stored in a pikofarad capacitor at a given voltage is E = 1/2 C V^2; for example, at 1 V across 1 pF, the energy is 0.5 × 10^-12 joules, illustrating the small scale of energy involved.

Measurement of small capacitances is commonly performed with LCR meters or impedance analyzers, which assess capacitance at a specified test frequency. Real-world capacitors also exhibit characteristics such as equivalent series resistance and voltage-dependent behavior that can affect measurements and circuit performance.