Book Review: Power Integrity
“Power Integrity: Measuring, Optimizing, and Troubleshooting Power-Related Parameters in Electronics Systems” by Steve Sandler
ISBN: 9780071830997 / 0071830995
Division: Professional & Medical
Pub Date: NOV-14
In some cultures like those in China and the near Himalayas, dragons are considered amulets to attract good luck. Author Steve Sandler surreptitiously includes a dragon figure at the beginning pages of this book, however, luck will not be needed since Sandler’s technical skills and his ability to communicate them will certainly make this book a success with electronics designers.
His practical techniques in test and attention to details regarding pitfalls and guidance in correct and accurate methods are a sure path to success for engineers to “do it right”. The inclusion of “actual” test data is key to provide designers with real-world effects that prove out mathematical models.
I wish labs in universities would follow Sandler’s book, especially in areas of fact-of-life limitations on test set ups and equipment limitations. No method is perfect. The engineer will need to also have a “gut feel” for the “ballpark” number in which a measurement should appear, otherwise some far out reading might not even phase the designer as he/she records it in a record book. Sandler’s guidance in this book emphasizes practicality and awareness.
I particularly like Sandler’s comments to suppliers about how important accurate and correct, real data and curves are to designers in a good data sheet. I come from a Burr-Brown background where technical marketing experts raised data sheet standards in the industry. In many cases we have strayed too far into the “sales and marketing” promotional versions of a data sheet. Designers have a right to demand real-world accuracy.
Sandler’s emphasis to test & measurement equipment developers to raise their awareness of the complex issues faced by design engineers on the bench and in the test departments of companies around the globe is a wake-up call to many.
And of most importance to me as an editor of EDN’s Power Management Design Center, is how Sandler focuses upon the fact that power supply performance is so very much critical to every electronic design system in the industry. His inclusion of modern GaN, eGaN, SiC and GaAs power elements are so very important in today’s power management designs.
And now, regarding the all-important topic of power distribution networks (PDN), with the necessity to measure extremely low impedances and amazingly high frequencies in power components and designs, Sandler focuses upon the best practices that he and his colleagues have used as “tried and true” methods to correctly represent the performance of a circuit in an actual environment in which it will be used.
The order of the chapters is very well thought out as well. First, the rationale behind measuring and data validation and then moving on to understanding the philosophy behind the measurement technique is presented. Next, on to the basic fundamentals of correct measurement and a discussion of test equipment with real examples of actual products gives the designer a setting for making the best and most accurate measurements they can hope for.
Moving on, the discussion moves to the subtle areas of avoiding added error and disturbing a system measurement with an in-depth discussion on proper use of probes, injectors and interconnecting devices.
Now the “meaty” chapters come, beginning with Chapter 6. After all the upfront education is given to the designer who wants to test a circuit or system, they will begin to embark upon the distributed power system and the right way to measure impedance, stability, power supply rejection ratio (PSRR), reverse transfer and crosstalk, step load response, ripple and noise, and edges. These are the important performance areas of a power design.
Troubleshooting is inserted at this point in Chapter 13 regarding near-field probes. We want to get this right or all of our measurements will be for naught.
Finally, the book finishes up with high-frequency impedance measurements, one of the most difficult areas for engineers to obtain an accurate result.
Watch for the book in Early November 2014 and visit McGraw Hill for purchasing details. This book would be sitting on my shelf as a designer years ago if it were available back then. But for those of you who want to make measurements correctly, I suggest following Steve Sandler who has certainly earned the reputation of doing it right. And it can’t hurt to have a dragon on your side as well.
- Profiles in Test: Steve Sandler
- Two common PDN measurement questions
- Power Integrity: It's not just decoupling caps