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.
The below introductory section features a video briefly discussing what exactly multi-phase buck regulators are, what applications they're suited for, and some of the challenges associated with implementing them. Additionally, the listed resources dive a little deeper into the topics covered in the video, providing further instruction in the beginning of your multiphase journey.
In designing with multiphase, Carmen works through a six-phase design for powering the core voltage of a networking ASIC, Marketing Manager George Lakkas explains why multiphase converters are ideal for high currents, and TI engineers blog about common concerns and use contexts.
In testing in the lab, Carmen takes a six phase buck regulator through basic validation testing in the lab with plenty of tips and waveforms shared. Let Carmen show you how to test transient response, input and output ripple, phase stability, and thermal performance. Additionally, TI engineers blog about various lab tricks related to multiphase devices.
PCB layout tips to manage heat dissipation with your switching regulator
Another way to manage thermals is through IC packaging. Smaller and smaller packages continue to be introduced as output currents trend upward. Learn more about the packaging technologies that aid heat dissipation under these challenging conditions and enable high power density.
If you want to learn from the mistakes of others, this session is for you. This practical presentation goes through a number of common mistakes in point-of-load DC/DC converter design and testing. With an engaging, interactive format, this session covers issues found in converter capabilities, component selection, control design, board layout and measurement techniques. The causes of the design mistakes and how to avoid them in future designs are explained.
Why should I take this training?
Loop gain measurements show how stable a power supply is and provide insight to improve output transient response. This four-part training video series discusses the theory of open-loop transfer functions and empirical loop gain measurement methods. It also demonstrates how to configure the frequency analyzer and prepare the power supply under test for accurate loop gain measurements. Examples are provided to illustrate proper loop gain measurement techniques.
The presentation addresses the design consideration of USB Type-C power delivery. USB Type-C is the new trend of Industrial, automotive and personal electronics devices. In the training, audience will be able to learn more about USB Type-C power delivery (PD) requirement and understand architecture of USB Type-C PD, AC/DC power source.