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Video: Measurement-Based, Harmonic Balance VRM Model

A presentation by Steven Sandler from Picotest, DgCon 2019 Modern high-performance power rail design requires high accuracy voltage regulator models, that include small signal and large signal responses. Electromagnetic simulation support is required in order to include parasitic details and accurate remote sense effects including the distributed decoupling design. Despite this long list of demands, the model must simulate quickly in order to be beneficial. A unified, fast-si

Webinar: Extending the Functionality of the Oscilloscope

Presented By: Steve Sandler, Founder and CEO of Picotest Duration: 54 minutes (available on demand) Sponsored by: Rohde & Schwarz Register now to watch on demand Abstract: Modern instruments are available to perform almost any measurement with extreme accuracy and resolution. Despite this, there has been a trend to include more capabilities within the most common of benchtop instruments, the oscilloscope. In past years, oscilloscopes have added basic additional features, su

EDI CON Online 2019: Characterizing the VRM

Title: Characterizing the VRM Duration: 30 minutes (Available On Demand) Presented by: Steve Sandler, Founder, Picotest Abstract: A high fidelity VRM model is required to properly assess system performance, and this includes power integrity (PI). This has always been my position and I have presented papers, videos and lectures on the topic. Most recently I wrote an article, published in the July 2019 Signal Integrity Journal, illustrating the interactions between the VRM and

Why Full VRM Characterization is Essential

Read the entire article here. #powerdistributionnetwork #noise #powerintegrity #ads #psrr #powersupply #inputimpedance #powerdeliverynetwork #voltagenoise #dcdcconverter #picotest #UltraLowNoiseVoltageRegulators #converter #bodeplots #controlloop #negativeinputresistance #targetimpedance

Measuring The Negative Input Resistance Of DC-DC Converters

Measuring the negative resistance of a DC-DC converter’s input requires introducing a perturbation of the input voltage while measuring the input voltage and the input current. Using a frequency response analyzer (FRA) or vector network analyzer (VNA), the modulated voltage divided by the resulting modulated current provides a direct measurement of input impedance. The Picotest J2121A line injector simplifies this measurement by integrating a modulator and a hall current moni

Optimizing Power for Clocks and other Sensitive Applications

Click here to read the entire article. #noise #Crosstalk #powerintegrity #noisesensitivecircuit #signalanalyzers #decoupling #vrts3 #capacitors #psrr #powersupply #impedancemeasurement #voltagenoise #j2111a #picotest #j2180a #power #impedance #regulator #clockjitter #controlloop

August Book Sale: Get Your Copy of Power Integrity for Only $65

PROVEN TECHNIQUES FOR GENERATING HIGH-FIDELITY MEASUREMENTS Power Integrity: Measuring, Optimizing, and Troubleshooting Power Related Parameters in Electronics Systemsprovides field-tested techniques for producing high-fidelity measurements using the appropriate equipment. The book thoroughly discusses measurement guidelines, test instrument selection and use, connecting the equipment to the device being tested, and interpreting the acquired data. The latest electronics techn

Characterizing and Selecting the VRM

The voltage regulator module (VRM) is at the foundation of power integrity, making proper selection essential. There are thousands of VRMs and VRM controllers available from many manufacturers. They are often selected based on size, efficiency, price, or a relationship with the manufacturer. This often leads to a poor VRM selection, requiring additional engineering resources, greater time to market, as well as higher BOM costs to correct the deficiencies. Even after the VRM o

Characterizing and Selecting the VRM

The Voltage Regulator Module (‘VRM’) is at the foundation of power integrity, making proper selection essential. There are thousands of VRMs and VRM controllers available from many manufacturers. They are often selected based on size, efficiency, price, or a relationship with the manufacturer. This often leads to a poor VRM selection, requiring additional engineering resources, greater time to market, as well as, higher BOM costs to correct the deficiencies. Even after the VR

Designing Power for Sensitive Circuits

What is a sensitive circuit? Sensitive circuits are those that can easily be degraded by power supply noise.  These circuits generally include oscillators, LNAs, transceivers, mixers and ADCs. I’ll probably receive emails from many readers adding to my list, and justifiably so, so take these as a few examples and not a comprehensive list. Click here to read the entire article. #noise #articles #j2120a #psrr #powersupply #impedance

Characterizing and Modeling Switch Mode Power Supplies (Mar 15)

Original air date: March 15, 2017 Why this Webcast is Important: Whether your power supply designs are based on switch mode or linear technology, there are many reasons why you should characterize the frequency response of your power supply designs. Two reasons are to better to understand the stability and noise immunity under various load change conditions based on an existing design. Another good reason is to gain the missing information required to create or improve a simu

Techniques for accurate PSRR measurements

By John Rice, System Engineer, Texas Instruments and Steve Sandler, Managing Director, Picotest Introduction In theory, measuring the power-supply-rejection ratio (PSRR) is relatively simple. A variable-frequency signal modulates the power-supply input, and the attenuation of that signal is measured at the output. However, the measurement is highly sensitive to setup noise, including noise from the probe-loop area and the layout of the printed circuit board (PCB). This artic

Troubleshooting Distributed Power Systems: Using Current Injectors (Part 5 of the ongoing video seri

Although not quite as accurate as the two-port VNA impedance measurement, the current injection technique has advantages including wide range (approx. 1 milli-ohm to thousands of ohms), the ability to measure in-system, and a suitability for measuring low-power devices such as op amps, voltage references and voltage regulators. In addition, current injectors can be used to carry out other types of tests such as non-invasively measuring PSRR, determining power integrity and si

FAQ#25: How do you measure PSRR of a linear regulator circuit that powers an oscillator for an ADC?

Steve Sandler Answers Your PSRR Questions (Power Electronics’ Q&A Series Follow Up) Earlier this month Power Electronics received a question about “How to measure PSRR of a linear regulator circuit that powers an oscillator for an ADC. How can I make this measurement using my oscilloscope?” We asked our expert in PSRR, Steve Sandler to weigh in on the subject and also encouraged readers to submit other questions they had about the space. Click here to read the Steve’s respons

Measuring Op Amp PSRR

One characteristic of Op Amps that limits the performance of low noise and precision circuits is PSRR. The output of the Op Amp is not only a function of the inputs, but also of the power supply. The PSRR of Op Amps is a frequency dependent function, so that the higher the signal frequency, the lower the PSRR is. In general, the manufacturers provide high fidelity data for PSRR, which might lead to the question of why we should measure it. There are several reasons that we sh

Are We Focused On The Wrong Reference Parameters?

Designing a reliable circuit that employs a voltage reference requires a more detailed look at device parameters than most data sheets provide. The key to optimizing the performance of any circuit begins with determination of the major performance criteria or “figures of merit” (“FOM”). Without a clear understanding of these key device parameters, circuit performance could be compromised. Figure of merit can vary depending on the circuit and application. Most engineers would

Measuring the PSRR of Voltage References

In this article we detail the process of measuring a key performance characteristic of voltage references, power supply rejection ratio or “PSRR”, using the Picotest J2120A Line Injector and the OMICRON Lab Bode 100 VNA. There are many types of voltage references, including series references, shunt references and several that can perform as either series or parallel devices. The general performance metrics include DC voltage accuracy, temperature coefficient, noise, output im

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