Capacitor and board distance

What is PCB layout for decoupling capacitors?

PCB layout for decoupling capacitors: The following diagram shows a simplified circuit model of the PCB stack of the power supply, IC and ground. PCB traces have impedance due to the finite dimensions, and it causes the voltage drop between the power rail and the power pin of the receiving ICs.

How do you put a decoupling capacitor on a board?

(My usual layout technique is to place the load, then place the power and ground vias, and finally place a decoupling capacitor on the opposite side of the board if there's room. (If there's no room, the capacitor moves, not the vias!)

Where should a bypass capacitor be placed on a PCB?

Refer to the schematic to ensure the placement of bypass capacitors at the device power pins and not at high logic pins. Capacitors are the most versatile components from the PCB assembly standpoint, and decoupling is one of their chief functions.

Where should a capacitor be placed in a BGA?

Implement the capacitor as near as possible to the IC pin to limit the propagation time. When you consider one nanosecond switching event, place the capacitor at half an inch of distance for a good power supply within the 20th wavelength. Usually, capacitors are attached to the bottom side of the board for BGAs.

Where should a capacitor and a via be placed?

Second best is to put the two vias on the same side of the cap, as close as possible to each other and the capacitor. An additional set of vias can be placed on the opposite side of the capacitor to cut the inductance in half, but make sure that the two via groups are at least a board thickness (or two plane distances) apart.

Where should capacitors be placed in a PCB?

The placement of capacitors is one of the most critical phases of the PCB design process. Incorrect capacitor placement can completely revoke their performance. Place capacitors on the bottom side of the board with respect to SMT component placement.