Articles by Steve Sandler

Extreme Measurements.jpg

The Ultimate Power Rail Noise Measurement

Do I really need to use a power rail probe to measure ripple and noise? Power rail probes are single ended, so does that mean I can only monitor one power rail at a time? Are there other, more affordable options available? In this blog post, Steve Sandler answers to these questions and more.


Read More
Extreme Measurements_FeaturedThumb_1

Determining FPGA Dynamic Load Current

In this Extreme Measurement story, the goal was to determine the dynamic current of the FPGA by measuring the AC current in an external VRM using a transformation of the PCB S-parameters and the simultaneous measurement of the AC voltages across the PDN.


Read More
Extreme Measurements_FeaturedThumb_1

A Bode Plot Without Access to the Control Loop

This extreme measurement seems more impossible than difficult.  The traditional stability assessment method for voltage regulators is the Bode plot.  Access to the control loop is required and a small signal is injected into the control loop, usually via a resistor, placed at the top of the voltage sense divider. Without access to this voltage divider, there isn’t a place to inject a signal into the control loop, and therefore the Bode plot is seemingly impossible…


Read More
Thumbnail_f4.jpg

Selecting a VRM Output Inductor

A consideration that is often neglected is the impact of the self-resonant frequency (SRF) or parallel equivalent capacitance, Cp, which is related to SRF. In this article, Steve Sandler focuses on the impact of the inductor SRF on switching regulator performance.


Read More