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Measurement and Application Expertise

Keysight Impedance and Network Analysis Application List

You face increasing technical and operational complexity. Keysight measurement and application expertise helps you anticipate these growing complexities.

Keysight impedance analyzers, LCR meters and ENA series network analyzers support various applications for impedance and network analysis. This catalog provides the information of unique and new solutions that we cannot tell all in product brochures. Please fi nd the solution that fi ts your case or helps your similar test challenge in this catalog, and contact Agilent to accelerate your business.

DesignCon 2010

Accuracy Improvements of PDN Impedance Measurements in the Low to Middle Frequency Range

Istvan Novak, SUN Microsystems

Yasuhiro Mori, Keysight Technologies

Mike Resso, Keysight Technologies

This paper discusses practical solutions for improving the quality and accuracy of frequency-domain Power Distribution Network (PDN) component measurements in the near-DC to MHz frequency ranges, which is gaining increasing importance in PCB-level applications of today’s low-voltage digital circuits. The paper discusses and illustrates how to measure the characteristics of DC-DC converters more accurately by understanding measurement accuracy, the limitations and error sources of different measurement systems. It also shows how to accurately characterize  Multi-Layer Ceramic Capacitors (MLCCs) and inductors/ferrite beads that have AC-signal and DC-bias dependences. The paper introduces new approaches to the milliohm impedance measurements and AC/DC-biased impedance measurements with a new 5 Hz-to-3 GHz Vector Network Analyzer (VNA).

Keysight E5061B Network Analyzer

Reverse Transfer Measurement
This application note shows how the reverse transfer characteristic of a linear voltage regulator (LM317) can be measured using the Keysight E5061B and the Picotest J2111A Current Injector. The same technique can be used to measure switching regulators as well.

Power Supply Crosstalk Measurement
This application note shows how the crosstalk characteristic of a system of two linear voltage regulators can be measured using the Keysight E5061B Network Analyzer and the Picotest J2111A Current Injector. The same technique can be used to measure switching regulators as well.

Testing LDOs requires you to have adequate instrument bandwidth
Most electronic systems contain at least one voltage regulator, with many systems requiring several regulators, each providing a different voltage.  The performance of these regulators is critical to the performance of the downstream circuits that they power.  Many important characteristics of these voltage regulators are either not specified by the manufacturer or worse, the data is incomplete or misleading.  The latter is often due to the limited bandwidth of the test equipment used by the device manufacturers in their testing.

Signal Injection Transformer
An injection transformer is a signal transformer that is connected between a network analyzer and a DC/DC converter or voltage regulator in order to both inject a perturbing signal and record the response over a wide frequency range. The goal of using a transformer is to measure the phase-gain response of the control loop without actually impacting the loop performance.  There is not much written about these devices, which is easily verified via a quick search on Google or your favorite search engine.  Much of what is published discusses why an expensive transformer is not necessary.  Much of what is written, even by manufacturers of the voltage regulators, is remarkably incorrect.

Non-Invasive Assessment of Voltage Regulator Phase Margin
Many voltage regulators are of the fixed variety.  A disadvantage to this approach is that the voltage divider is not available for Gain-Phase or “Bode” measurement.  This leads many to believe that it is not possible, or even necessary to evaluate the stability of the regulator.  Neither of these beliefs are true. This article demonstrates how to determine the control loop phase margin of a voltage regulator, without breaking any connections and using only an inexpensive Vector Network Analyzer (VNA) and a Picotest J2111A current injector.

Network Analyzer Signal Levels Article
When measuring a circuit or device with our network analyzers, engineers generally inject a signal and believe that the measured results reflect that of a small-signal AC measurement. Many of us have been taught to keep the signals “very small”. This raises the questions, “how small is very small” and “is this an issue with my network analyzer”?  SPICE based circuit simulators use partial derivatives to perform small-signal analysis, and therefore, are not sensitive to the signal level; regardless of the AC magnitude the results are linearized and scaled. So how big can an injected signal be before it significantly impacts a measurement? Let’s investigate the answer via a simple test.

Measuring PSRR with the J2120A and E5061B
This application note shows how the Power Supply Rejection Ratio, or PSRR, of a linear voltage regulator (LM317) can be measured.

Measuring Optocouplers with J2130A
Many power supplies use optocouplers in the feedback loop.  The stability and overall performance of the power supply are often dependent on the CTR and the location of the poles (and zeros) of the optocoupler.

Introduction to Signal Injectors
The network analyzer is a common piece of equipment in most of our labs today. They can vary in features but regardless of the analyzer being used, the analyzer oscillator signal must be injected into the circuit being tested in order for a measurement to be made.

A Simple Method for Designing Stable Regulators
A single, simple measurement is described that allows the determination of the ESR required to achieve a desired phase margin, using a particular value of output capacitor. Solving the ESR requirement at the lowest operating current provides a stable solution for higher operating currents as well.

Voltage Regulator Test Standard Manual
Manual describing how to perform various test using the Picotest Signal Inejctors