Automate Power Supply Testing with PulseLoad Pro
- marshall3463
- Aug 15
- 4 min read
What are the Challenges with Manual Transient Step Load Response Testing
Measuring power rail transient performance in response to high current dynamic loading is essential for power integrity validation. The behavior of power rails during transients is critical for system stability, and both steady state and transient responses must be analyzed. This is because modern digital components, like FPGAs, CPUs, and GPUs, demand fast, stable power, and any voltage fluctuation—or "transient"—can cause system instability or performance issues. These voltage fluctuations are related to the energy absorbed or dissipated in the system and PDN, as part of these electric circuits plays a key role in determining the magnitude of these transients.
However, many engineers spend hours manually adjusting a waveform generator and oscilloscope, trying to capture the exact transient step load response of a VRM or power supply. During this manual process, engineers are generally looking for the steady state value and phase of the voltage output after a transient event. The process is repetitive, and due to the limitations of most scopes, only a few waveforms can be compared at a time. This results in limited measurement data or a stack of screenshots that must be compared manually. But what if we told you there was another way? In this article, we will show you how to use PulseLoad Pro to automate this process, saving you time and providing all of the data you want.
What is PulseLoad Pro and How Does it Help?
PulseLoad Pro is an easy-to-use software that enables users to gather more data in less time by automating the processes of measurement gathering and data analysis. The equipment and tools used in the setup, including the oscilloscope and power supply, are specified to ensure accurate measurement of signals and voltages during transient events. To use PulseLoad Pro, you can connect your MXO5 oscilloscope and NGL202 power supply to your computer over Ethernet to the same local area network or use a USB hub. Then, on the MXO5, connect an S10 Load stepper to the waveform generator 1 output, and a P2105 probe to channel 1. Finally, connect your DUT to channel 1 of the NGL202 with banana cables, and land both probes close together on Vout; then the setup is complete.
Using the GUI, users only need to specify the following variables, each of which defines the function and operation of the test. These specifications are critical for maintaining system performance and stability under different loads:
PSU Select: Allows the user to select which of the computer's connected devices is the Power Supply Unit.
Voltage [V] & Current [A]: These will be set as the power output settings of the PSU, determining the voltages and current delivered to the DUI.
O-Scope Select: Allows the user to select which of the computer's connected devices is the Oscilloscope.
VRM Vout [V]: Specify the output voltage of the VRM (DUT).
Start Frequency [KHz]: Specify the minimum frequency for the sweep.
Stop Frequency [KHz]: Specify the maximum frequency for the sweep.
Log Measuring: (True/False) whether the program should measure in log scale (1, 2, 3, ..., 8, 9, 10, 20, 30...), or just increment from the start frequency (10, 20, 30... 80, 90, 100, 110, 120).
Duty-based pulse width: (Duty Cycle/Pulse Width), whether the pulse width used to drive the step load should be calculated based on duty cycle or set to a fixed pulse width.
Minimum Duty Cycle [%]/Pulse Width [ns]: specify the value of the respective setting.
Once that is set up, you simply hit "RUN," and the test automation software will do the rest for you. The software will perform a series of tests that reveal different transient behaviors of the system. To start, the software will run a sweep of all the responses to determine the scale of the worst response, allowing it to auto-scale all the waveforms and avoid clipping. It will set the scale and trigger level based on the auto-scaling, then sweep through the frequencies again, recording the measurements this time. During the measurement process, the software captures multiple raw time-domain voltage signals after each transient event, which allows the software to post-process the data in multiple formats. The results are presented in a specific form for further analysis.
Finally, it will analyze all the measured data, determine which frequency had the worst-case voltage ripple, and then display it, along with the seven surrounding frequencies, as reference waveforms on the oscilloscope. It will then use a built-in post-processing MATLAB package to graph all the measured waveforms together, as well as their voltage ripple Vs. frequency.
In this demo example, the software generated over 24 different measured responses in under a minute and determined the worst response to be at 40 kHz. More measured responses can be captured if desired; users only need to specify that in the PulseLoad Pro GUI before running the application.
If you want to see a live demo of PulseLoad Pro in action, check out the video below.
What can engineers achieve with PulseLoad Pro?
PulseLoad Pro transforms the way engineers approach VRM and power supply testing. This powerful software automates the entire process, from capturing transient responses across a wide range of frequencies to identifying and displaying the worst-case waveform in just one minute. Instead of spending hours on manual adjustments and sifting through countless screenshots, you can get all the data you need for post-processing in a fraction of the time.
Ready to streamline your workflow and dramatically reduce your test time? Learn more about the PulseLoad Pro Product Bundle, which includes everything you need for a complete, out-of-the-box solution, including the software, a configured oscilloscope, a power supply, and specialized probes.
If your testing needs are unique, we also offer custom test automation solutions to help your team solve even the most complex applications.
Ready to revolutionize your testing process? Check out the PulseLoad Pro Product Bundle or Contact Us for custom test automation solutions.
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