Filter Capacitor

Filter Capacitor

Filter capacitors are capacitors used for filtering of undesirable frequencies. They are common in electrical and electronic equipment, and cover a number of applications, such as:

• Glitch removal on Direct current (DC) power rails
• Radio frequency interference (RFI) removal for signal or power lines entering or leaving equipment
• Capacitors used after a voltage regulator to further smooth dc power supplies
• Capacitors used in audio, intermediate frequency (IF) or radio frequency (RF) frequency filters (e.g. low pass, high pass, notch, etc.)
• Arc suppression, such as across the contact breaker or 'points' in a spark-ignition engine

Filter capacitors are not the same as reservoir capacitors, the tasks the two perform are different, albeit related.