It is commonly known that ceramic capacitors change capacitance with applied voltage. What isn’t always as well known is how strong this effect can be and why it occurs. At KEMET we’ve put together a technical video that answers that question.
What is Ask An FAE?
Ask An FAE is a new video series we launched at my day job, KEMET. An FAE is a field application engineer. These engineers are very common in the electronics industry. Companies like KEMET, where I work, have FAEs who meet with customers to answer technical (and very detailed) questions about how to use their products. In UBM’s Mind of an Engineer survey, FAEs were ranked as one of the top information sources for design engineers.
At KEMET we decide to use FAEs to answer the questions. While I’m not an FAE today, I was in the past and happy to kick off the series with our CEO.
A switching voltage regulator is one of my favorite circuits. In school, they were the first circuits I built where I understood how transistors worked. In fact, they were the first circuit I saw an inductor being useful! Switching regulators are incredibly efficient when designed properly. Of course, this detail about design is important. They are not as simple as a linear regulator, which is basically an IC and two caps.
To understand the basics of a switching regulator, I released AddOhms #18 this week. This is video tutorial dedicated the Switching Voltage Regulator. If video tutorials aren’t your thing, then keep reading for my written tutorial.
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Hardware Developers Didactic Galactic is a group for hardware designers, hackers, and enthusiast to discuss hardware-related topics. HDDG11 (or 0xb) featured a presentation from SnapEDA CEO on Footprints and my presentation on Capacitors.
Titled “They’re JUST capacitors?” I used content from my time as a KEMET Field Application Engineer.
In the presentation I address the common myth or guideline: “capacitors should be derated 50%.” Comparing Aluminum, Ceramic, and Tantalum we discuss why each technology has a de-rating associated with it. Turns out, they all have different reasons to de-rate.
Additionally I give a brief introduction to Supercapacitors. (You’ll note that it is spelled with one word…) The key to understanding what makes them “super” relies on how they achieve the common capacitor structure of electrode plate, dielectric, electrode plate.
Whether you are an engineer with enough experience to be called a graybeard or a novice that keeps grabbing the wrong end of a soldering iron, there is one component that eludes everyone working in electronics.
It’s the humble capacitor.
A seemingly simple device, turns out, to be incredibly complex. While the basic electrode-dielectric-electrode structure sounds simple, the materials used in that structure drastically changes the characteristics of the device.
On every page of my blog, you might notice a chat window. If I’m not busy, we can chat in real-time. If not, the messages come to me by email. Here’s one I got from Matt the other day:
Let’s talk a bit about how (and why) you would use a P-Channel MOSFET. Matt, and he’s not the only one, is probably asking this question based on the “myth” that P-Channel MOSFETs require “negative voltage” supplies.
To save time, breadboard pins or just lack of knowledge people try to skip adding eve one decoupling capacitor to a circuit. Either on IRC or in Forums you can almost always see it coming: “randomly, my circuit stops working” And then, “what do you mean a decoupling capacitor?” question.
While working on breadboard Arduino, I came across some unexpected measurements. Initially, the only capacitors on the breadboard were the two 22pF from crystal to ground and the capacitor connected to RESET for Auto-RESET.
Karl and Corey run The Spark Gap Podcast which is focused on embedded electronics. On Episode 25 they interview me about Capacitors. We covered all the major types of caps, plus some application bits. Check out their show notes for an impressive array of links on the subject.
Also, my favorite episode of theirs so far is episode 18. The guys talk about different serial protocols like SPI, I2C, CAN, etc. Really good stuff.
January 28, 2015
Capacitor Questions Answered on The Spark Gap Podcast
Understanding what X2 or Y1 capacitors actually are and are not is important when designing them into an AC-mains connected power supply. Recently Electronic Products Magazine ran an article I wrote on the proper role of X and Y safety rated EMI Capacitors.
The X2 capacitor rating means different things to different people–except for UL. When I wrote this article to discuss some common misconceptions around what X2 Rated Capacitors are, and how they can be properly used.
In case the PDF reader doesn’t load, it’s on Page 20 of the November 2014 issue.
“There is no Moore’s Law for passive components like capacitors, but relentless development is delivering the kinds of devices engineers need to deliver cutting-edge new products for modern living. Capacitors have for many years enabled electronic designers to manage energy within circuits and fulfill basic functions like filtering noise or harmonics, correcting power factor, stabilizing feedback circuitry, coupling/decoupling, interfacing between voltage levels, and storing energy. But the demands placed on these components continue to increase, as electronic devices are expected to be smaller, longer lasting, more feature rich and more robust.”