There are moments in our field when a new set of requirements arrives, fundamentally changing how we approach our work. We lived through this with EMC—and those of us who were there remember both the uncertainty of those early days and the satisfaction of watching our community rise to meet it. It is rising again. This time, cybersecurity is leading the charge.

For years, the industry has treated cybersecurity as a software problem—something for IT departments to manage after products leave the drawing board. That’s no longer good enough. Regulators on both sides of the Atlantic have made clear that security must be designed in, not bolted on.

atchdogs have long been a standard, if slightly esoteric, element of system design, often receiving only secondary consideration after the primary application has been planned out. At their core, they serve a straightforward purpose: providing a graceful means of recovery in the event of abnormal system behavior. At their origin, watchdog timer architectures were simple, implemented via a dedicated application-specific integrated circuit (ASIC), positioned adjacent to the system’s processor (see Figure 1).

In that early form, interaction with the watchdog was typically limited to a simple general-purpose input/output (GPIO) pin. However, as systems have grown in complexity and adopted stricter safety requirements, watchdog implementations have also evolved. In more modern setups (see Figure 2), a watchdog may be integrated into the microcontroller itself, reside in a voltage monitor or supervisory device, or be part of a power management integrated circuit (PMIC), often refreshable through GPIO, I²C, or SPI.

ithium-ion cells and batteries produced in or imported into China are now regulated in accordance with China’s Compulsory Certification (CCC) system. The China State Administration for Market Regulation (SAMR) announced CCC requirement for lithium-ion cells and batteries used in portable electronic equipment through Notice No. 10 issued in 2023.¹ Effective August 1, 2024, all regulated lithium-ion cells and batteries must be CCC-certified for compliance with the requirements set forth in GB 31241.

GB 31241, “Lithium-ion cells and batteries used in portable electronic equipment – Safety technical specification,” was originally issued in 2014 and more recently replaced by the 2022 version, GB 31241‑2022.² GB 31241-2022 is not equivalent to any current international standard. However, relevant reference standards include, but are not limited to, IEC 62133‑2:2017,³ UN 38.3 (7^th Revision),⁴ and UL 1642:2020.⁵

n the age of digital health, connected medical devices are transforming patient care. From insulin pumps and glucose monitors to smart inhalers and wearable ECGs, these devices deliver real-time data, enable remote monitoring, and improve clinical outcomes. However, as connectivity increases across devices, so does the risk of cyber attacks. For engineers tasked with designing these devices, security by design is more imperative than ever for compliance.

IL-STD-461 RE102 is probably the most commonly failed test in the aerospace/defense world, with 50-90% of units failing their first pass testing. This is a frequent cause of schedule delays, first for troubleshooting, and then for all the meetings needed to process waivers. There are ways that it can be tailored, even very early in the product development process, to minimize the need for waivers after test failures. Any time a unit fails a test but is allowed to move forward after going through a waiver process, it’s an indication that the requirements were not set appropriately at the beginning of the program.

Ultimately, we want to do the minimum amount of testing that gives us the best assurance of mission success. We don’t want to over test and jeopardize cost and schedule targets. But we also don’t want to under test and miss something that could cause issues on the integrated platform. Understanding the purpose behind RE102 requirements helps us tailor them in a program‑specific way.

rom the time that Heinrich Rudolf Hertz first demonstrated the transfer of electrical energy from one antenna to another in the late 1880s, humanity has witnessed, observed, and enjoyed the fruits of electromagnetic radiated fields. The electromagnetic waves first produced by Hertz in his lab in 1886 were proof that James Clerk Maxwell’s 1864 theory of “electromagnetic waves” was correct.

Hertz published a series of papers in the last years of the 1880s that verified the characteristics of the “Hertzian Waves” with respect to frequency, amplitude, speed (velocity of light), and other physical parameters. Hertz never realized the practical importance of his discovery and did not explore the applications of the “Hertzian Waves,” which became known as “radio waves” over time.

he shift from internal combustion engine (ICE) automobiles to electric vehicles (EVs) has come with an array of new subsystems and components that introduce new EMC considerations. The level of complexity involved in automotive electromagnetic compatibility (EMC) testing increases with dynamic driving conditions, where manufacturers not only have to refer to the framework standards offered but must also improvise and establish new internal standards to ensure the vehicle and its internal components all function properly under all driving conditions. A number of challenges may arise when building a suitable test bench that thoroughly tests EVs and electrical components.

This article discusses the importance of EMC testing in the automotive industry, as well as dynamic EMC test systems and their inherent challenges. It also describes the development of a unified EMC test platform for dynamic driving conditions.

n 1967, while on patrol in the Gulf of Tokin, the United States Navy Carrier USS Forrestal was executing wartime missions over North Vietnam. At 10:45 AM local time, the ship was preparing to launch more than 27 A-4 Skyhawk and F-4B Phantom Fighter jets, all fully fueled and armed with a mixture of iron bombs, precision missiles, and Zuni rocket launchers. At 10:51 AM, an F-4B experienced an un-commanded Zuni missile launch on the flight deck, striking a neighboring A-4 and starting a fire causing a series of devastating secondary explosions. Quenching the fire nearly capsized the ship, which was ultimately saved through the heroics of the sailors who served aboard the Forrestal.

n 1967, while on patrol in the Gulf of Tonkin, the United States Navy Carrier USS Forrestal was executing wartime missions over North Vietnam. At 10:45 am local time, the ship was preparing to launch more than 27 A-4 Skyhawk and F-4B Phantom Fighter jets, all fully fueled and armed with a mixture of iron bombs, precision missiles, and Zuni rocket launchers. At 10:51 am, an F-4B experienced an un-commanded Zuni missile launch on the flight deck, striking a neighboring A-4 and starting a fire, causing a series of devastating secondary explosions. Quenching the fire nearly capsizes the ship, which is ultimately saved through the heroics of the sailors who served aboard the Forrestal.

Although the US Navy conducted an extremely thorough accident investigation, many subsequent technical articles in the aerospace and NASA literature, including current EMI design books, blame the initiation event on EMI from the onboard AN/SPS-43 VHF search radar. This article is aimed at reinforcing the official USN record regarding the accident’s true root cause. The Forrestal’s many “lessons learned” led in part to the creation of an entirely new discipline called “insensitive munitions” within the Electromagnetic Compatibility community and is therefore a critical event to understand.

ISPR is the International Special Committee on Radio Interference which was founded in 1934. The International Standard for electromagnetic emissions (disturbances) from industrial, scientific, and medical (ISM) equipment is CISPR 11. The official title of the standard is “Industrial, Scientific, and Medical Equipment – Radio-Frequency (RF) Disturbance Characteristics – Limits and Methods of Measurement.”

The premiere edition of the standard was released in 1975, and the current edition (seventh edition) was released in 2024. The standard includes both limits and methods of measurement for conducted emissions and radiated phenomena. This article details the most recent Edition and retroactively traces the history and development of the content of the standard over the last 50 years.

he Dunning–Kruger effect¹ explains how overestimating one’s technical reach can narrow ESD evaluations to the decades‑old floor resistance-to-ground (Rtg) test—an essential metric since the 1950s, yet blind to system interactions. Three case studies show that skipping resistance tests of mobile technical elements (casters, chairs, carts) that depend on the floor as a series path to ground leads to false confidence and missed risks.

This article advocates pilot floor installations plus insitu body voltage, probability analysis of charge generation data, and mobileelement resistance tests to validate system-level performance and secure long-term staticrisk mitigation.

ince the first observations of interference from unknown events with AM radios in the early 1920s, the field of electromagnetic interference (EMI) has continued to evolve and involve more than AM radios. Today, any product with a power cord or that is battery‑operated can and will generate electromagnetic fields. Electromagnetic compatibility (EMC) testing is required for any product that has electrical, digital, and/or radio components.

With the growth of the variety and volume of those products, the time to complete EMC testing typically takes longer, due to competition for lab time, and for surprises in tracking down short-burst or impulse‑type emissions. The automotive industry, for example, requires exacting methodologies to measure all emissions accurately. Long test times impact test facility availability and potentially reduce the number of devices that are certified. It’s also easy to miss intermittent disturbance signals with conventional scans since an extended dwell time must occur at each frequency.

ur internal EMC laboratory had decided to verify (not certify, as it’s not an accredited lab) all the equipment we use for pre-compliance EMC tests. The goal was to find some defective equipment and to repair or replace it to avoid the possibility of generating inaccurate test results.

One of the trickiest pieces of equipment to verify was the ESD gun because specialized equipment is needed for the verification test. Off-the-shelf ESD targets are relatively expensive (>1500 USD), so we decided to build a do-it-yourself (DIY) version. (See our final design in Figure 1 and Figure 2.)

have always wanted to write articles on filter design. Needless to say, the subject alone can easily spawn a book. This is because, in the world of electronics, we have power filters, transformers, low-frequency filters, digital circuit filters, and analog circuit filters. Each design requires its unique and dedicated filter design principles. Additionally, we have different requirements, and it is fair to say that most commercially available filters are designed to meet certain EMC specifications. Hence, they are most likely designed to work efficiently with the test setup, particularly the line impedance stabilization network (LISN) for conducted emission tests.

Given the numerous points to consider, capturing everything in one article is nearly impossible. My favorite books and articles on this subject are listed in the reference section [1]-[3], and I encourage readers to explore them.

n Part 1 of this series of articles¹, we provide an overview of EMI filter design for switch-mode power supplies (SMPS). In this part, we will examine specific aspects of switched power converters. The goal is to help readers understand:

5. Input and output capacitors

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