Definition

Decoupling provides local charge storage near IC power pins to supply transient current demands faster than the power supply can respond. Decoupling capacitors filter high-frequency noise and maintain stable voltage during load switching. Effective decoupling requires capacitors with low ESL (equivalent series inductance), short trace lengths to component, and a hierarchy of values covering different frequency ranges. Embedded capacitance provides decoupling at frequencies where discrete capacitors become ineffective (typically above 100-500 MHz).