I recently had the chance to review a new RF signal generator from Trinity Power Inc. Their model TPI-1001-B is much more than just a mere synthesizer. This improved model also includes several modulations as well as scalar analysis (a "poor man's" network analyzer). The product (Figure 1) is available from RF design consultant, Robert Yarbrough … [Read more...]
Top Three EMI and Power Integrity Problems with On-Board DC-DC Converters and LDO Regulators
Co-authored by: Kenneth Wyatt and Steve Sandler INTRODUCTION Modern devices are continuing a long-term trend of squeezing more electronics into smaller packages, while also increasing system performance, data rates and operating efficiency. Higher efficiencies are often achieved by implementing faster silicon MOSFETs or even faster eGaN FETs while size is reduced by … [Read more...]
EMI Troubleshooting – Step-By-Step
In this article, I’ll describe the steps I usually take to troubleshoot the top four EMI issues, conducted emissions, radiated emissions, radiated immunity, and electrostatic discharge. Of these, the last three are the most prevalent issues, with radiated emissions typically being the number one failure. If your product or system (EUT) has adequate power and I/O port filtering, … [Read more...]
HDMI Cables and EMI
As more consumer and commercial products are introduced with High-Definition Multimedia Interface (HDMI) cable connections, the resulting EMI issues related to HDMI cable emissions have continued to be problematic for product designers and EMC engineers. It is very common to have one, or more, added HDMI cables cause a product to fail the radiated emissions (RE) test. The … [Read more...]
Platform Interference – Measurement and Mitigation
As a consultant, I'm seeing an increasing number of manufacturers wanting to add or retrofit wireless into new or existing products. Products typically include mobile, household, industrial, scientific, and medical devices. Also, the trend toward the “Internet of Things” (IoT) or the Industrial Internet of Things (IIoT) adds to the problem. This transition towards "everything … [Read more...]
Get the Job Done – Pocket-Sized 20 MHz Wireless Oscilloscope
In photography, they say the best camera is the one you have with you. The same may be said for simple electronic test equipment. For example, I was recently working with a client and we needed to verify Vcc voltage on one of their boards. Not having a DMM quickly available in their lab, I pulled out a tiny DMM from my troubleshooting kit, no larger than a pack of cigarettes. … [Read more...]
Developing an In-House EMC Troubleshooting & Pre-Compliance Test Lab
While investing in your own full in-house EMC test laboratory may seem difficult to justify, most companies should be able to afford to implement some level of pre-compliance testing capability. Outside compliance test labs can cost upwards of $2,000 per day. The advantage of being able to perform some of the key tests in-house is that you can quickly determine whether your … [Read more...]
Review: EMC – Methods, Analysis, Circuits, and Measurement
Electromagnetic Compatibility - Methods, Analysis, Circuits, and Measurement, David Weston, CRC Press, 2017 (3rd edition) While I've reviewed many books on EMC, this one by David A. Weston, is the most complete in coverage yet. The 1157-page book covers not only basic and advanced theory of EMC, but includes product design, commercial and military measurement techniques, and … [Read more...]
Measuring Common Mode Versus Differential Mode Conducted Emissions
When faced with excessive conducted emissions from switching power supplies, one of the first things to investigate and to determine the adequacy of is the power line filter. Line-powered switching supplies generally have both common mode and differential mode sections of the filter as shown in the generalized schematic in Figure 1. When using a line impedance … [Read more...]
ESD Effects of Digital ICs
One issue I see fairly often with unshielded consumer or commercial products is CPU resets during periods of immunity testing, such as during electrostatic discharge (ESD) testing. Untreated, this can lead to field failures and associated customer satisfaction issues. The remedy is usually quite simple and IC manufacturers even mention the solution, but it’s usually buried … [Read more...]
