Articles by Eric Bogatin

Just how good are VNA Measurements?

Just because someone has a VNA capable of 60 GHz bandwidth doesn’t mean it will always give the same results. It is not the instrument, but the measurement procedure that seems to influence the quality of the measurements the most.  Read on for information on a recent study from Jason Ellison, Heidi Barnes, and Jose Moreira  as well as 7 tips for improving your measurements.


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The Future of Power Integrity

Get six experts in a room together and you are likely to hear seven different opinions. Not so at the Future of Power Integrity Panel Discussion at DesignCon 2019.  The consensus of this panel of experts is that the future of power integrity will include single processor chips drawing as much as 1000 A and more. Read on for the details of this discussion!


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Avoid These Two Artifacts When Measuring SMPS Power Rails

Switch-mode power supplies (SMPS) are commonly used DC-to-DC converters in many electronic components. By their nature, they can generate a lot of radiated emissions. Unless care is taken, it is difficult to separate what is the actual voltage on the power rail and what is an artifact due to the way we probe the circuit. The project outlined here shows how to avoid EMI pick-up and cable reflection noise.


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Quick, Simple Way to Measure the System Bandwidth of a Scope-Probe System

While we get the scope’s bandwidth from the vendor, as soon as we add a cable, probe, or amplifier to the scope, we decrease the system bandwidth. The new system bandwidth is as important to know as the scope’s bandwidth, but it is generally difficult to measure except in a calibration lab. We offer a simple method of evaluating the transfer function and system bandwidth of any probing system using a wide band noise source. This method not only gives us information about the probes and interconnects, but it also tells us how the scope responds to the measurement system, information which cannot be measured by a VNA alone.


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Target Impedance Is Not Enough

Target impedance has become a standard tool when designing a power distribution network (PDN). It establishes a limit to the highest impedance the power rail on the die should see looking into the PDN. If the PDN impedance stays below this limit, even the worst-case transient current from the die will generate an acceptably low rail voltage noise.


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