Coupling capacitors allow AC components to pass while blocking DC components. Decoupling capacitors are used in electronic circuits as energy reservoirs to prevent quick voltage changes. Bypassing capacitors clean DC signals by shunting unwanted AC components to ground.
Coupling capacitors are used in electronic circuits to pass the desired AC signal and block unwanted DC components. These unwanted DC signals come from electronic devices or preceding stages of an electronic circuit. In audio systems, DC components affect the quality of the desired signal by introducing noise.
If space is not an issue, polypropylene and polyester capacitors have characteristics that make them a good choices for coupling applications in pre-amp circuits. Some electronic circuits are highly sensitive to voltage spikes, and rapid voltage changes can greatly affect their performance.
Capacitors are fundamental components in both analog and digital electronic circuits. They are used for a wide range of applications including coupling, decoupling, filtering, and timing applications. Coupling capacitors allow AC components to pass while blocking DC components.
When using AC-coupling in optical transceiver design, care should be taken to minimize the deterministic jitter associated with the low-frequency cutoff of the AC-coupling network. This application note discusses how to choose AC coupling capacitors that fit system requirements. Read full article.
When selecting a capacitor for coupling/DC blocking applications, the key parameters to consider include impedance, equivalent series resistance, and series resonant frequency. The capacitance value primarily depends on the frequency range of the application and the load/source impedance.