Istvan Novak

Istvan Novak

Istvan is a Principle Signal and Power Integrity Engineer at Samtec, working on advanced signal and power integrity designs.  Prior to 2018 he was a Distinguished Engineer at SUN Microsystems, later Oracle.  He worked on new advanced power distribution design and validation methodologies. He was responsible for the power distribution and high-speed signal integrity designs of SUN's successful workgroup server families. He introduced the industry's first 25 um power-ground laminates for large rigid computer boards, and worked with component vendors to create a series of low-inductance and controlled-ESR bypass capacitors.  He also served as SUN's representative on the Copper Cable and Connector Workgroup of InfiniBand, and was engaged in the methodologies, designs and characterization of power-distribution networks from silicon to DC-DC converters. He is a Life Fellow of the IEEE with twenty five patents to his name, author of two books on power integrity, teaches signal and power integrity courses, and maintains an SI/PI website.

ARTICLES

Making a Steamy, Hairy Golf Ball

My friend Steve Sandler pointed out a major hurdle we face in power distribution design: power engineers (who design power converters) and power integrity engineers (who design system bypassing-decoupling networks) use different vocabulary, techniques, and requirements. To understand a little better how we got here, I want to start with a prediction I heard sometime in the early 90s at one of the conference keynote speeches: “In 10 to 20 years, computers will look like hairy steamy golf balls.” 


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Preamplifier Options for Reducing Cable-Braid Loop Error

When measuring low impedance with the two-port shunt-through configuration, we potentially create an error due to the resistance of cable braids.  This error can be reduced or eliminated by using appropriate preamplifiers. There are professional preamplifiers on the market that do a great job reducing the cable braid error.  If you want to experiment with your own circuit, this article will help you


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Overview and Comparison of Power Converter Stability Metrics

Power conversion circuits with control loop(s) are everywhere in electronic systems. We must establish stability and performance metrics for control loops and their circuits. However, generally accepted metrics may not be good enough. Is a crossover frequency with 45 degrees of phase margin and 10 dB of gain margin enough? How can we relate phase margin to peaking in the impedance profile and transient noise requirements? This article aims to answer these and other questions.


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Transient Load Tester for Time Domain PDN Validation

Power distribution networks (PDNs) delivering power to ICs in a system need to be thoroughly designed and analyzed in order to make sure any voltage fluctuation on the rail is within the tolerance of every IC connected to that rail.  As ICs on the rail draw power, they generate a voltage fluctuation on the rail.  The PDN must have the capacity to supply enough charge such that the resulting voltage drop is less than the maximum voltage drop each IC on the rail can tolerate.  If voltage fluctuations appear outside IC tolerance limits, a slew of problems can surface such as IC damage, failure, or reduced lifespan.


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Current Sharing Measurements in Multi-Phase Switch Mode DC-DC Converters

This paper, presented at EDI CON USA 2017, demonstrates the use of a special probe tip utilized to convert a differential measurement of inductor voltage to a measurement of inductor current. It shows the connection and calibration considerations in the measurement of inductor current, including the digital signal processing algorithms required to compensate for the components in the power supply and the probe tip. It also explains current sharing measurements made in the time and frequency domain using a transient current generator.


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How Much Capacitance Do We Really Get?

We have to use enough capacitors so that the PDN functions properly. At the same time, to keep cost and size in check, we want to avoid overdesign and not use capacitors unnecessarily. Read on for advice on how to find the balance.


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