Power Hotspot

Sometimes it's easy to tell if you have a safety margin. With a voltage regulator, or any linear amplifier, if it was oscillating, you could add a fix - often, a simple series R-C network from the input or output to ground. Good. But is it good enough? To be safe, you should put in a square wave of voltage (or pull out a square wave of current through a little R-C network) and make sure that there isn't any bad ringing. Now, to be quite sure, you would have to...

Don't write off lithium-ion (Li-ion) batteries just yet, but their competition is gaining ground. Formerly known as Zinc Matrix Power Inc., ZPower appeared at last month's Intel Developer Forum (IDF) in San Francisco to discuss an early, unnamed adopter of its technology as well as reveal more about its plans to get around the high cost of silver. It all hinges on a plan to get companies that recover silver from used X-ray film to start...

We know Class D audio amplification offers advantages in efficiency and size for battery-powered devices. What you may not know, however, is that these advantages can now extend to amplifiers up to 500 W thanks to solid-state driver ICs designed specifically for Class D. Systems based on these new ICs outperform Class AB when it comes to THD+N measurements and simplify the designer's job by accepting ground-based analog audio inputs. Other attractive features include overcurrent...

Despite great strides made by electronic system designers in developing products that perform sophisticated tasks, engineers may encounter performance-limiting factors beyond electronic circuitry - like thermal management. Even if good design practices and reliable components are in place, system reliability can suffer if appropriate temperature controls are not implemented. That's why circuit designers should have a basic understanding of how to manage operating...

As IT managers deploy new applications in the data center, bandwidth demand is outstripping capacity. Applications such as video streaming and the relentless demand for storage are pushing IT networking infrastructures beyond their limits. At the same time, IT managers are under pressure to reduce power consumption in the data center as well as the total cost of ownership (TCO). Fortunately, the next evolution of Ethernet is approaching deployment readiness. The...

While scientists at the turn of the 20th century were experimenting with the wireless transmission of information, like radio, Croatian-born inventor Nikola Tesla had a grander vision (Fig. 1). He imagined the wireless transmission of power—to supply "light, heat, or motive power anywhere—on sea, or land, or high in the air," he told The New York Times in 1904. With the help of the October 2006...

When I joined Vicor almost 20 years ago, the inventors of the brick told me that the planar surface of a base plate is optimal for removing or transferring heat and that potting provides an outstanding thermal interface around each component. When bricks first came out, in fact, all of them were encapsulated and fitted with attached base plates. Our philosophy at the time, as it is now, was to be as flexible as possible to enable designers to adapt the brick to many different...

Adjustable three-terminal voltage regulators made their debut in Electronic Design in an April 12, 1977 article called "Break Loose From Fixed IC Regulators" by Robert Dobkin, then an IC designer at National Semiconductor. Dobkin had adapted National's bandgap-based fixed regulator to make it adjustable via a voltage divider on the output. The divider's center tap is applied to the anode of the regulator's voltage reference (see the...

While most electronics research has its twists and turns, a project currently under way at the Georgia Institute of Technology offers more than its share of new angles. That's because the research is entirely focused on bending things. Georgia Tech researchers are investigating how simple bends made in nanowires, using a kind of molecular origami, can lead to a completely new class of electronic parts. "We're utilizing the coupling of piezoelectric and...

According to Jay Sandvos, a partner with Bromberg & Sunstein LLP, a Boston law firm focusing on intellectual property and business litigation, the recent Supreme Court decision makes it much easier for the Patent Office to reject claims as obvious just by adding together pieces of different prior-art references to resemble the claims. In the past, this had to be supported by an analysis. Such analysis would have to demonstrate that someone in the same field...

PMBus products first hit the market in 2005, and since then, we've seen a steady stream of releases. September 2005: Artesyn Technologies announced its first digital point-of-load (POL) converter. The DPL20C is a non-isolated POL converter in the new family of PMBus-compliant dc-dc converters. The DPL20C is a 20-A output converter that features an extensive set of digital configuration, monitoring, and diagnostic facilities accessible via the PMBus interface. This...

Power-One's patents cover digital power management and control incorporated in its Z-One system architecture, which controls distributed point-of-load (POL) regulators from a single digital power manager. One of the patents (6,949,916, issued September 27, 2005) is "System and method for controlling a point-of-load regulator." It describes the use of serial bus control (either passively or actively) for a point-of-load (POL) regulator. Here, the...

Sure, designers of embedded computer systems know digital techniques. But they may not be intimately familiar with the digital management of the power supplies used by their systems. Two methods reign when it comes to implementing digital power management. Yet it's not clear which method will win the favor of system designers—or the favor of the courts. Power-One's proprietary Z-One system was the first method to arrive. Then came the open-standard Power...

I just returned from a two-week family vacation driving through Italy and Greece, exploring the roots of Western civilization. While I was on the road, I realized how power-addicted we Westerners have become, as each night's rest stop included a ritual of lithium-ion (Li-ion) charge-ups. I remembered to buy a 220- to 110-V converter before leaving on the trip. But I didn't realize that there was going to be a nightly "charging queue" with five of us in the family, each...

So what's happening in medium-sized power supplies? These days, the power output is the only thing that's medium-sized as these smaller devices provide more power density. Aimed primarily at the telecom market, XP Power's 12-, 24-, and 48-V dc output MFA350 may hold the current record for the world's smallest 350-W supply, cranking out 11.2 W/in.3 in its base version. That's 364 W across the entire 90- to 264-V ac input range from a 3.2- by 6.8- by 1.5-in....

It’s summertime, but the living isn’t easy. All the talk about global climate change— coupled with soaring summer electric rates—is keeping me from keeping my cool. According to the Edison Electric Institute (EEI), 60% of a typical summer electric bill is devoted to air conditioning, and that could jump to 75% based on the weather. I live in a century home, and I don’t have central air. Between the attic fan, the dehumidifier in...

The draft standard for IEEE 802.3at Power over Ethernet Plus (PoE Plus) remains on track for an August release. The original 802.3af PoE standard offered a fairly straightforward way to supply loads with 13 W or so of usable power delivered at 48 V dc. But IEEE 802.3at PoE Plus, which ups usable power to something over 50 W, introduces some wrinkles that designers and even IT managers must understand. One catch is that designers can still supply power in a limited...

Now that the dust is beginning to settle on the European Union’s Restrictions on Hazardous Substances (RoHS) directive, what’s next? What new environmental legislation will change the way the indus- try designs its products? It pretty much comes down to two key words: energy efficiency. The EU will phase in its Energy-Using Products (EuP) directive beginning in August 2007. Like RoHS when it was first introduced, the EU is still tweaking the language...

Garbage is power. At least that's true for Jerry B. Warner, president of Defense Life Sciences, which is developing a trash-to-electricity generator. The fact that the company is working on a "green" energy technology isn't unusual. What's out of the ordinary is that Warner happens to be a retired U.S. Army colonel, and his prime customer is his former employer. The U.S. military is investigating green technologies—particularly environmentally friendly power-generation...