Picotest and SES solutions address TAPI concerns.

You may not have heard of TAPI, but you will. By necessity, testing extreme dynamic transient conditions is becoming more and more common for measuring, analyzing, and optimizing PDNs for next-gen computer systems.

Products like Picotest’s S2000 custom GaN dynamic transient load solution and Signal Edge Solutions PulseLoad Pro automated power supply solution address TAPI test needs for generating time and frequency domain load activity profiles exceeding 2kAmps/ns are now available.

TAPI stands for Time-Aware Power Integrity. It’s a methodology (and in some contexts, a specific analysis toolset) for analyzing power integrity (PI) in electronic systems with respect to both the frequency domain and the time domain.

Traditional power integrity analysis often focuses on frequency-domain impedance (e.g., AC power plane impedance versus frequency) or time-domain transient simulations separately. TAPI unifies these views by making the analysis time-aware, meaning it accounts for when current is drawn from the power delivery network (PDN) and how fast it happens.

Here’s a breakdown of what TAPI time-aware power integrity involves:

Dynamic Current Profiles (Time-Aware Loads)
- Instead of assuming a generic step load or averaged switching current, TAPI uses actual activity patterns of FPGAs, processors, or ICs to model the current transients in time.
- These realistic profiles better predict voltage droop, overshoot, or resonances.
PDN Impedance + Transient Behavior
- TAPI links the measured/simulated PDN impedance with the time-domain load behavior.
- This allows engineers to evaluate whether the PDN can support worst-case bursts of current without violating voltage tolerances.
Resonance and Timing Sensitivity
- A PDN may look “stable” in the frequency domain but still fail in time-domain conditions if the load current spectrum excites a resonance at just the wrong moment.
- TAPI reveals these vulnerabilities by correlating time-based load events with frequency-domain impedance peaks.
Use Cases
- High-speed digital systems (e.g., DDR, SerDes, CPUs, GPUs, FPGAs).
- Power supply validation under real switching activity.
- Identifying power integrity margin more realistically than static worst-case assumptions.

In short:
Traditional PI = “Do I have a low-enough impedance across frequency?”
TAPI PI = “Given when and how the chip demands current, will my PDN deliver it without timing-induced failures?”

It’s especially useful because real systems rarely operate at pure worst-case conditions all the time. TAPI lets engineers see time-aligned risks (like simultaneous switching events or power-on transients) that standard PI may miss.

Here are some Tools for Measuring dynamic power rail transient performance for power integrity validation.

Picotest S2000A – 2000+ Amps/ns transient load stepper