2.3.1 Requirements

Low-impedance decoupling/filtering of the device power supply inputs must be provided. A 100 nF ceramic X7R (or X5R, X7S) capacitor placed very close to each power supply input is a minimum requirement. A 4.7 µF ceramic X7R (or X5R) ceramic capacitor should also be placed on the VDDCPU, VDDUTMI, VDDIN33 and VDDIODDR power rails, close to the MPU. The VDDCORE power input should have two 4.7 µF ceramic capacitors placed close to the MPU.

A 2.2 µF X7R (or X5R) ceramic capacitor should also be placed close to the VDDOUT25 power output pin.

The VDDANA and VDDDPHY power inputs should be connected to the VDDOUT25 power output.

In the SAMA7G54-EK design, we opted for 100 nF 0201, X7S rated at 16V and 4.7 µF 0402, X5R rated at 10V multilayer ceramic capacitors with good results. Small sized capacitors provide better decoupling due to reduced inductance.