In power integrity analysis, we primarily concern ourselves with the impedance response when evaluating the frequency domain. Specifically, we focus on the magnitude of the impedance response and tend to neglect the phase of the impedance response. After all, the phase can be extracted from the magnitude: Flat impedance magnitude across frequency is purely resistive with 0° phase -20 dB/decade slope is purely capacitive with a -90° phase +20 dB/decade slope is purely inductive with a +90°...

When we teach about S-parameters and modeling, someone never fails to ask “What is causality?” or “What happens if a model isn’t causal?” Our go-to explanation is that it's a cause and effect thing: a system is causal if its output doesn’t respond before its input changes. In a causal universe, the light shouldn't turn on before you flip the switch. This seems straightforward. After all, if you're modeling or measuring a physical system — say, interconnects between a driver and receiver —...

Transient voltage responses of a PDN subjected to periodic step loads. Large signal measurements are essential to Power Distribution Network (PDN) validation. By stressing the PDN, they reveal transient phenomena that are otherwise difficult to surface. This article discusses capturing large signal phenomena with the Picotest P2105A (S10) Transient Load Stepper browser probe. We recently explored Large Signal Phenomena using the MXO5 - Sequential Trigger Measurement Setup. PDN large signal...