Design

Wireless technology is experiencing explosive growth. More than just devices of the same kind, there is a proliferation of applications that take advantage of wireless connectivity, using it in new and novel ways. Wireless technology itself is developing and radio access technologies are becoming increasingly complex and sophisticated. The result is that today’s electromagnetic environment is changing. This means that old test methods and limits are no longer adequate to insure systems have adequate electromagnetic immunity.

Although the foundation of a failure analysis is rooted in science, there is also an art to completing one, successfully. The path from problem discovery to problem solution has many bumps and twists along the way. This article will hopefully help guide you on that journey.

Most of you know NEBS has something to do with telecommunications. It’s true; NEBS has a lot to do with telecommunications. NEBS is the premiere set of documents used to ensure telecommunications equipment perform at their highest level possible.

The development of “digital common-mode noise” within circuit devices and subsequently within circuit boards is initially formed by peak over-shoot and under-shoot currents in the power and return planes. The peak currents are attributable to the “cross-conduction” transitions in circuit devices, where the driver literally segments turning “on” before the pull-down drivers turn “off”.

This article is the second in our ongoing series about batteries. This installment provides an overview of lithium-ion batteries – typical properties, principal applications, and trends.

The reliability of electronic technologies (including the software and firmware that runs on them) can become critical when the consequences of errors, malfunctions, or other types of failure include significant financial loss, mission loss, or harm to people or property (i.e. functional safety).

The board stackup is probably the most essential piece for ensuring a successful PCB design. Modern high-speed busses require controlled-impedance traces, and whether you are using a simulation tool, a simple calculator, or the back of a napkin, you need to understand your manufacturing process to correlate your impedance calculations. This ensures that your trace widths and dielectric heights match what will actually be manufactured, and eliminates last-minute design changes.

An equivalent dipole model is proposed in this paper to represent the source of radiated electromagnetic emissions from an integrated circuit (IC). The height of an IC is usually much smaller than its length and width, so only three dipole moments are sufficient to characterize an IC in terms of its electromagnetic emissions. The dipole moments can be extracted from three TEM cell measurements. The radiated fields from the IC can then be calculated based on the extracted dipole sources. This IC emission model with three dipole moments is validated using the far-field measurements in a semi anechoic chamber for a test IC. For complex structures, it is desirable that the extracted dipole moments can be incorporated into a commercial full-wave tool as equivalent sources to simulate the radiations from an IC. This is demonstrated using an approach developed in this article.