Before we dive into specific application-based examples of noise and EMI mitigation, let's start with the basics. What is noise? What is EMI? What is ripple? How are they measured? What are some common approaches to limiting their effects? This section discusses these topics with a more conceptual approach to serve as a primer for the rest of the series.
Now that we understand the sources of EMI and noise in switching regulators, and some of the common approaches to mitigating each, let's take a closer look at real-world examples of reducing their effects. In this section we will examine the impacts of various mitigation techniques to help you decide which approach makes the most sense in your design. Techniques covered in this discussion include external component placement, filter options and design, frequency manipulation via spread spectrum or dithering, snubbers, boot resistors, and more.
Noise and EMI can be detrimental to sensitive analog signal chain circuitry. For this reason, many engineers automatically default to linear regulators. But, in doing so, they are essentially trading one problem (noise) for another (heat dissipation). In this section we will discuss what types of signal chain loads can be driven directly by a switching regulator to get low noise and EMI without sacrificing efficiency. We will also discuss when a linear regulator is absolutely needed to reach levels of noise not possible with a switcher.
Because of the potential havoc that interference can wreak in radio and safety critical systems, automotive electronics are subject to the most stringent EMI standards- the most common being CISPR25 Class-5. The materials below provide a discussion around the sources of EMI in an automotive environment and a comprehensive blueprint to understanding how to minimize it's effects.
In this training series, we will touch the gate driver applications, fundamentals of low side gate driver, high- and low side gate driver and isolated gate driver. And we will surely go deep and help you understand the gate driver design considerations with TI reference design and the corresponding critical waveforms.
When it comes to MOSFET datasheets, you have to know what you’re looking for. While certain parameters are obvious and explicit (BVDSS, RDS(ON), gate charge), others can be ambiguous at best (ID, SOA curves), while others can be downright useless at times (see: switching times).
In complicated power designs, metal-oxide semiconductor field-effect transistor (MOSFET) selection has a tendency to be somewhat of an afterthought. While it’s just a three-pin device, appearances can be deceiving and trying to select the correct MOSFET or “FET” can be a task more complicated than you might think. In this 7-part blog series, we analyze a variety of typical FET applications, from power supply to motor control, and address the various concerns and trade-offs that dictate the FET selection process.
For anti-tampering, it is common to try to detect the presence of a strong magnet. In this section, we will cover the use of hall sensors for low-power detection of strong magnetic fields in three dimensions. Details on our magnetic tamper detection reference design, TIDA-00839, will be provided as well as some of the design considerations that were kept in mind when creating this reference design.