Distance between Coupling Capacitor and voltage pins

[Azhar Latif]

Is it necessary to place coupling capacitor near Ic voltage pins.

[randychase]

It depends on other factors (such as sensitivity of the IC) as to how important it is, but putting them closer to the voltage pins is considered important.

My normal goal is to place decoupling caps very close to the power pins. Some people think it is important enough to not allow the power lead to connect to the power plane directly, but only after going to the cap.

[Skip Yutkus]

It is important, actually when possible bypass caps are frequently placed directly on the fanout vias of a BGA - the purpose is twofold, to eliminate noise generated by the bypassed IC when switching, (power fluctuations), and to lessen noise introduced by other IC's.

Skip