Power integrity

For instance, a noisy power supply can cause audible or visible disturbances or slow down data communication.

The effectiveness of PI engineering is measured by the overall system performance, even though it specifically addresses power supply circuits.

In other words, PI engineering identifies circuit blocks that are sensitive to power supply perturbations and requires careful attention.

PI is essential for achieving successful signal integrity (SI) engineering, which deals with impedance matching among multiple elements.

[2][3] As a microprocessor transitions between idle and heavy computation states, it draws rapidly changing current from its power supply unit, often referred to as a voltage regulator module (VRM).

Dynamic current occurs when the consumer switches its transistors, typically triggered by a clock signal.

It is therefore necessary to utilize multiple capacitors of different sizes to ensure a low PDN impedance across the frequency range.