The Global Positioning System (GPS) is a worldwide, RF wireless-based system for determining where you are anywhere in the Earth’s surface if there is line-of-sight visibility to at least four of its orbiting satellites. The availability of GPS since its inception a few decades ago has not only enabled products and features which were simply […]
FAQ
e-Fuses, Part 2: Building or buying an e-Fuse
The electronic fuse is a powerful and versatile tool in the designer’s kit, but building one requires careful selection of the core amplifier; IC embodiments solve the problem. Part 1 of this FAQ looked at the basic structure of the electronic fuse or e-fuse. This part looks at the requirements on the current sense amplifier […]
Why use an e-fuse? Part 1
The electronic fuse is a powerful and versatile tool in the designer’s kit, but building one requires careful selection of the core amplifier; IC embodiments solve the problem. The traditional thermal-based fuse, Figure 1, is a low-cost, widely used, well-understood, highly reliable, easy-to-apply circuit- protection component. It is available in a wide range of ratings, […]
20 mA current loops, Part 2: Advanced features
Part 1 of this FAQ looked at the basics of the 20-mA current loop, why it is still used extensively, and its primary attributes. In this part, we’ll look at how the analog current loop is used for digitized signals and at self-powered loops – two developments which have extended its life and viability. Q: […]
20-mA current loops, Part 1: Basic functions
You’ve been given an “easy” assignment: get the low-rate data from a temperature sensor to a control computer located 100 feet (30 m) away, in an industrial setting. After much investigation and assessment, you choose a widely used standard called the 20-mA loop, which has been in use for over 50 years, rather than Wi-Fi, […]
Electrical noise, Part 2: Additional perspectives
In Part 1, we looked at some facets of noise: sources, external versus internal (intrinsic) noise, and equations. Part 2 goes further into noise specifics. Q: What are some of the types of noise? A: It’s a long list. The same noise may have different names depending on the perspective of the person describing it, […]
Electrical noise, Part 1: Introductory concepts
Electrical noise is a consideration that engineers think, talk, worry, sometimes obsess about, and deal with nearly all the time, with few exceptions. In many applications, it is the limiting factor on ultimate achievable system performance. If it were not for the existence of noise, many design situations would be far, far easier. Noise is […]
Active noise cancellation, Part 2: Implementation
Part 1 of this FAQ looked at the basic concept of active noise cancellation, how it might be implemented in principle using analog circuitry, and the harsh reality of actually providing the ANC function. Part 2 looks at modern ANC systems and how they function, as well as their practical issues. Q: Is ANC using […]
Active noise cancellation, Part 1: Concept and principles
Electrical noise, whether due to internal circuit external signal sources, is an ever-present factor which ripples through many aspects of the engineer’s design challenge. But there is another kind of noise – namely audio/ acoustic noise – which affects consumers and the individuals, and whose affect engineers are striving to reduce. This noise can affect […]
RF/Microwave noise, Part 2: Noise temperature and applications
Part 1 of this FAQ looked at the basic specifications of noise factor and noise figure, widely used in RF/microwave system and circuit analysis to predict and assess both requirements and performance. This part looks at the additional parameter of noise temperature, as well as the impact this parameter has on system performance. It also […]