Innovating essential high technology systems with demanding specifications is always challenging; making any sort of difference requires extensive resources and deep subject matter knowledge.

But that’s what keeps it interesting.

With the challenges of today’s global supply chain, we understand that improving the efficiency of your development process is critical to delivering quality products on time. When evaluating components for use in your product, you don’t have time to wait 2–3 weeks for a product sample. And you certainly don’t have the time to wait another 2–3 weeks if you discover that the sample you ordered isn’t right for your design. That’s why Knowles Precision Devices is now offering all-in-one Single Layer Capacitor (SLC) Design Kits for design engineers.

In a previous article about electric vehicles (EV), we talked about using DC link capacitors as an intermediary buffer in power converters. Today’s topic covers another useful power module component – the snubber capacitor. Snubbers are energy-absorbing circuits used to protect electronics from voltage spikes and transients caused by turning a switch from the On to Off state. Opening a switch intrinsically induces a high voltage across the device, and the snubber provides an alternate flow path for the excess energy to be absorbed by the snubber capacitor and dissipated by a resister or other load.

Multilayer ceramic capacitors (MLCCs) are made up of two materials—ceramic dielectric material and metal electrode material. Layering metal electrodes and ceramic dielectrics (Figure 1.) achieves voltages that are capable of producing high electric fields that ultimately allow MLCCs to regulate current flow and prevent electromagnetic interference between components. There are two common electrodes used in MLCCs: precious metal electrodes (PMEs), containing palladium silver, and base metal electrodes (BMEs), containing nickel or copper. Each electrode type holds a spot in the capacitor world for a reason.

Healthcare professionals and patients rely on magnetic resonance imaging (MRI) technology to examine soft tissues and organs in the body to detect a variety of issues, from degenerative diseases to tumors, in a non-invasive manner. To do this, the MRI machine uses a strong magnetic field and computer-generated radio waves to produce cross-sectional images. Thus, the quality of the MRI depends on the uniformity of the magnetic field – even the smallest trace of magnetism inside an MRI scanner can disrupt the field and degrade the quality of an MRI image. 

Today, many electrical systems are demanding higher operating voltages and temperatures, along with higher capacitance values – particularly in the fast-growing area of power electronics for electric vehicles (EVs). Therefore, electrical design engineers are looking to use multilayer ceramic capacitors (MLCCs) in these applications due to their inherent low inductance and wide operating temperature range.

Impedance, measured in ohms, extends the concept of “opposition” to alternating current (AC) applications. It accounts for resistance, the opposition of current flow, and reactance, the measure of opposing alternating current – an effect of inductance and/or capacitance. In direct current (DC) applications, we talk in terms of resistance, not reactance. Chances are: This isn’t new information. But there’s a reason we wanted to cover this topic – impedance values play an important role in capacitor selection.

Space missions present a unique set of environmental challenges that demand high reliability down to the smallest electronic components. Mission failures could cost human lives. From in-flight systems to power supplies, every single system contributes to the success of a space project, so they must maintain high quality and safety standards for long durations.

In electric vehicle (EV) applications, filter capacitors are a special type of component commonly used as input and output capacitors. Also known as noise suppression or electromagnetic interference (EMI) filters, these particular capacitors act to remove noise and other unwanted signals on the line. On the high voltage alternating current (AC) side of a system, the capacitors often provide EMI filtering, whereas on the direct current (DC) side of a subsystem, they serve to smooth ripple components of the AC and filter out noise.

To help customers with filter selection, we generally provide a lot of information on what our filters can do. But in this new Filter Basics Series, we are taking a step back to cover some background information on how filters do what they do. Regardless of the technology behind the filter, there are several key concepts that all filters share that we will dive into throughout this series. By providing this detailed fundamental filter information, we hope to help you simplify your future filtering decisions. 

To kick-off this series, our first post breaks down the basic properties impacting capacitor and inductor performance including resistance, capacitance, inductance, and impedance.