EMI filtering plays an important role in reducing noise that could interfere with other devices; in medical or defense applications, for example, false alarms due to external interference could be detrimental. Here, we will continue our EMI filtering exploration with application and installation considerations. For earlier reading, review EMI filtering basics and filter performance.

To comply with international legislation such as the EU Directive on EMC or the FCC, EMI filtering is an essential element of equipment design. Here, we will continue to explore EMI filtering through insertion loss and filtering performance.

The insertion loss performance shows signal attenuation at any given frequency. As a metric, the insertion loss performance is most useful as a guide in the filter selection process; the actual performance in service can vary depending on circuit characteristics.

In mission-critical applications, additional screening and testing is required to ensure that only the most robust parts make it to the finished product. Preventative measures, like high quality standards, lessen the possibility of failure in the field and minimize the likelihood of astronomical downstream costs.

Supply noise creates challenges in RF systems where it can mix with RF signals, impacting signal-to-noise ratios and potentially causing spurious output. Thus, high-frequency monolithic microwave integrated circuit (MMIC) amplifiers with broadband gain need to be protected from RF noise on the supply lines. Avoiding these issues with supply line noise requires RF designers to use a bypass capacitor that provides an efficient path to ground for RF energy on the supply line before it enters a gain stage (Figure 1).

Imaging systems account for a significant portion of the medical devices and electronics industry. There is an expanding range of imaging modalities, and one of the most common is magnetic resonance imaging (MRI). MRI equipment uses a strong magnetic field and computer-generated radio waves to create cross sectional images of the body; these images enable health care professionals to investigate and diagnose without the need for an invasive procedure.

Compared to other applications, a medical implant is a rather benign environment for a capacitor; it’s temperature-controlled with a relatively low voltage. That being said, the success of a capacitor in a medical implant relies heavily on manufacturing components to avoid failures and the know-how to screen for any production discrepancies. As the reliability grade of a component progresses, more screening and testing is required to ensure that only the most robust parts make it to the finished product.

The advantages of multilayer ceramic (MLC) capacitors over plastic film types include their smaller physical size, lower inductance, and ability to operate at higher temperatures. These advantages make MLC capacitors very well suited to high power applications, such as power converter systems in electric (EV) and hybrid electric (HEV) vehicles.

Multi-layer ceramic capacitors (MLCC) are a highly efficient, robust, and mature product that are enabling rapid innovation across a myriad of industries and expanding numbers of applications. However, with global demand for these critical components at an all-time high, at the moment there is a global shortage in their supply – especially in the traditional, non-specialized geometries. As MLCC demand is fueled by significant product development in the IoT, consumer electronics, and electric vehicles (EV), new advancements in these industries have become limited to the capacitor’s availability during the shortage, with lead times reaching several months to a year in some cases.

The worldwide electric vehicle (EV) market is exploding in demand and mainstream adoption as governments push for fuel economy improvements and automotive companies look for new market opportunities. According to Forbes, “by 2020, EVs are likely to cost the same as conventional fuel powered equivalents.” Major manufacturers – like General Motors, Toyota, and BMW – plan to release “a mouthwatering potential of 400 models and estimated global sales of 25 million by 2025.” For EV design engineers and purchasing agents, this drive towards increased electrification results in the challenge of finding cutting-edge components that can handle increasing temperatures, voltage, and power without sacrificing reliability, availability, and footprint.