Five Essentials for Trusted Device Characterization

As electronic devices become more complex and embedded across industries such as wireless telecommunications, medical and healthcare, automotive, and consumer electronics, the need for precise electronic device characterization has never been greater. Characterization enables engineers to understand physical and electronic device behavior under various operating conditions, identifying a device’s strengths and weaknesses and guiding design improvements that enhance overall functionality and performance.

Device characterization enhances quality and reliability by analyzing how a product behaves under temperature and physical stresses. It also helps improve manufacturing processes to increase product quality and yield.

This white paper outlines five fundamentals for device characterization so you can uncover trusted test insights.

Configure Your Setup to Produce Precise and Accurate Measurements

Precision and accuracy are key factors in enhancing device characterization. Outlined below are three areas to focus on, using a digital multimeter (DMM) as an example.

Choose the right instruments for the job

Do not underestimate the importance of selecting the right instruments for the task at hand. Verify that they meet the necessary specifications and performance standards. For example, while many modern DMMs have 6.5 digits, they may lack measurement stability, especially when measuring extremely low voltages or currents. This instability is evident when poor repeatability causes the least significant digits to fluctuate during measurement. The stability of the least significant digit greatly impacts the accuracy of your results, especially when measuring very small signal applications.

The Keysight Smart Bench Essentials Plus DMM provides an accuracy of 35 ppm DC voltage over a year. While many brands claim to meet certain test ranges and accuracies, they may not be rigorously tested against important test and metrology standards such as ISO / IEC 17025 or safety standards such as IEC 61010 and CSA. Check the test instrument company’s regulatory website for declaration of conformity documents to verify quality, safety, and metrology standards. Keysight provides such documents on its product environmental and regulatory compliance website.

Reduce measurement errors from the test setup

The test setup and the instruments themselves can introduce measurement errors. Signal interference, unfiltered external noise, and internal current leakages are common errors. Test probes sometimes introduce loading errors.

Figure 1 illustrates a common measurement error caused by the test setup: a finite ground loop connection caused by different ground potentials between the test fixture and the instrument. This discrepancy introduces unwanted noise errors.

To eliminate this ground loop error, maintain the test instrument’s isolation from the earth’s ground; do not connect the input terminals to the ground. If the test instrument must be earth-referenced, be sure to connect it and the device under test (DUT) using the same common earth ground point. This process will reduce or eliminate any voltage differences between the devices.

Well-designed test instruments, such as the Smart Bench Essentials Plus DMM, provide proper grounding isolations and very high input impedance to prevent such ground loops. For more information on how to reduce measurement errors with a DMM, read this white paper: Eliminate Measurement Errors and Achieve the Greatest Accuracy Using a DMM.

Configure instruments to optimize precision and accuracy

Careful consideration of how you configure your instruments is crucial to obtaining precision and accuracy. For example, there is usually a trade-off between the speed and precision of your measurements. Figure 2 shows a chart of speed versus resolution for a Smart Bench Essentials Plus 6.5-digit Truevolt DMM. The higher your measurement throughput speed, the lower the resolution you get for your measurements. Hence, there is a sweet spot that you need to find as an engineer. Typically, a development engineer characterizing a product will optimize for higher accuracy and precision. A manufacturing engineer, on the other hand, may consider good enough accuracy to prioritize higher test throughput or speed.

Another trade-off that can affect the accuracy of your measurement is averaging — for example, increasing the averaging of your measurements to reduce random noise. This will help you get more accurate measurements but at the expense of speed because of the real-time averaging processing power required.

If you understand what kind of noise you need to remove, you can selectively remove it using features available in modern instruments. This process is often more effective than using the brute force of high-averaging counts in your configuration. For example, suppose you want to remove power line cycle-induced AC noise that is affecting your measurement. In that case, you can use the Keysight Truevolt power line cycle (PLC) integration time function with its built-in analog-to-digital converter. Other features, such as AC and DC block filters, also help remove unwanted noise.

This white paper also offer four other strategies — ranging from calibration techniques to data analysis — that build on the fundamentals of good measurement practice and help streamline workflows, minimize errors, and ensure consistent, reliable outcomes across development and manufacturing environments.