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.

Check out KEMET’s Ask An FAE

I was invited to speak at the 11th Hardware Developers Didactic Galactic group at the Supplyframe office in San Francisco. I talked about the misconception that capacitors are a simple device.

Chris Gammell recorded the discussion and posted it via PHY Media. This video is about 50 minutes.

In this talk, I break down a few things to know about Ceramic, Aluminum, Tantalum, and Supercapacitors. You can see the full video via PHY Media’s YouTube Channel: They’re JUST Capacitors. For links and the slides, check out this post.

Switching Voltage Regulator Tutorial

AddOhms #18 covers the basics of switching voltage regulators

Switching Voltage Regulator - AddOhms Banner

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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HDDG11 Capacitors and FootprintsHardware 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.

Overview

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.

Download PDF (11mb)

Tools mentioned at the HDDG11 Presentation

For Questions

Questions related to capacitors or this content, should be asked through the KEMET’s Contact Us.

Cool learning resource: KEMET Engineering Center

Filling the capacitor gap between school and the real world

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.

KEMET Engineering Center Mockup

KEMET Engineering Center Screenshot, Courtesy of KEMET Corporation.

There’s a new website created by KEMET Electronics which aims to educate all levels of engineers about the ins and outs of capacitors. They call it the KEMET Engineering Center.

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P-Channel MOSFET Tutorial with only Positive Voltages

From the mailbag (or chat… bag?)

Positive Voltages with a P-Channel MOSFET Tutorial

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.

Keep reading for a how to use only positive voltage in this p-channel MOSFET tutorial.

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Can a 1µF decoupling capacitor be too much?

What happens when a breadboard Arduino skips a decoupling capacitor or two

1uF Decoupling Capacitor Circuit

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.

Keep reading to find out what happen when I added a 100nF and a 1µF cap. A bunch of scope traces and surprising results follow.

Breadboard Arduino with no Decoupling Caps

Breadboard Arduino with no Decoupling Cap

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The_Spark_Gap

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.

Date:January 28, 2015
Appearance:Capacitor Questions Answered on The Spark Gap Podcast
Outlet:The Spark Gap Podcast
Format:Podcast

10818399_10152509408852219_5757913693783094151_oUnderstanding 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.

You can see the full article with the EP Reader, by clicking here.

Date:November 1, 2014
Appearance:Role of EMI X1, X2, Y1, Y2 Capacitors Ratings
Outlet:Electronic Products Management
Format:Magazine

Article I wrote on some innovations KEMET has implemented in their capacitors:

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.

Read “Capacitor Innovations Address Emerging Opportunities” on Power Systems Design.

Date:December 30, 2014
Appearance:Capacitor innovations address emerging opportunities on PSD
Outlet:Power Systems Design
Format:Magazine