decoupling capacitor

Decoupling capacitors are used to decouple the supply voltage from interference voltage or switching pulses from the processors.

Decoupling capacitors are connected into the supply voltage of the chips and smooth out interference pulses from the processors so that they do not affect the supply voltage. On the other hand, they also prevent voltage peaks from reaching the functional units via the supply voltage and impairing their functionality.

Decoupling capacitors should be placed in the immediate vicinity of the processors because interference pulses can be radiated in via longer conductor paths. In order to be able to dissipate the parasitically radiated interference peaks to ground, the capacitive reactance of the decoupling capacitors should approach zero so that only the equivalent series resistance( ESR) is effective. Low inductance chip capacitors( LICC) are particularly suitable for use as decoupling capacitors. With their terminals on the longitudinal side, they have a particularly low equivalent series inductance( ESL).