Power Hotspot

Solar-power researchers at the Massachusetts Institute of Technology (MIT) have been very busy in their labs lately, and not without significant fruits for their labors. Two projects promise to elevate solar power from an expensive and cumbersome alternative to an affordable and unlimited energy source. SOLAR POWER GOES GREEN-LITERALLY! Relying on the process of photosynthesis occurring in plants for inspiration, MIT...

Power designers often prefer particular power products or manufacturers. Some designers try to drive these preferences into every application. That’s not surprising. Such choices are usually based on successful relationships with specific manufacturers. The designers already know the products, or they can rely on a level of reliability, on-time delivery, or good prices. Many suppliers of dc-dc converters offer common input and output voltages, power levels, and features....

Ceramic capacitors are rapidly increasing in capacitance and volumetric efficiency (CV/cc) due to higher dielectric constants and smaller dielectric thickness as well as higher layer counts. To compete with ceramic capacitors and meet demands for miniaturization, tantalum (Ta) capacitors also need to increase their volumetric efficiency. Traditionally, the only way to increase CV/cc in Ta capacitors was to reduce particle size in the Ta powder, thereby...

With the mass proliferation of mobile devices and various computer and homeentertainment peripherals, most of us suffer from a bad case of wall warts. Doug Palmer, a principal development engineer at the San Diego division of the California Institute for Telecommunications and Information Technology (Calit2), uses the phrase “wall warts” to describe the plethora of external power supplies that vie for position in his and our wall sockets and power strips...

As digital-camera and phone-camera resolution increases, high-resolution image sensors require more light. Firstgeneration low-res camera phones provided barely adequate flash intensity for taking closeups of friends at parties. Even second-generation camera-phone flash is still unsuitable for image sensors with greater than 3-Mpixel resolution. And that’s just talking about still photography. Video requires in-phone camera lighting to provide...

The mobile version of the WiMAX broadband wireless technology is beginning to roll out as laptop manufacturers add it to their PCs and as other companies make wireless access points for the home and office. Now, all of these designers have access to a WiMAX power amplifier (PA) thanks to SiGe Semiconductor. The SE7262L is a 2.5-GHz PA for batterypowered devices. It delivers 28.5 dBm of output power (708 mW) with an efficiency of 20%—not bad...

A few engineers were having a debate. According to all the books, some of them said, op amps are supposed to have zero output impedance, or very low. That means the output voltage wonâ??t change, just in case the output current changes. Some older op amps had an output impedance of 600 ? or 50 ?. So, the gain of the amplifier wonâ??t change just because the load changes. That must be good. But a couple of other engineers pointed out that many modern op...

Power-added efficiency (PAE) is the ratio of the difference of the power gain of an RF power amp to the dc power that amp consumes. In commercial wireless systems at 175 and 500 MHz in cell phones at 800 and 900 MHz, it’s customary to use two MOSFET stages in the final output, running off a 3.6-V rail. For those typical applications, Renesas has applied a new process technology to boost PAE. The n-channel first-stage RQA0014 has 55% higher PAE than...

HI BOB, I am trying to build a test circuit that will produce a pulse current from a capacitor. My target is around 200 A at 100 ms. Is this possible? We have an instrument called a PVI that does the same only at lower current and at shorter duration, but I don’t know how it is being controlled. I hope you can give me advice or a basic control circuit that I can start working on. –ROMMEL C. VILLON HELLO, MR. VILLON, You...

By moving digital feedback and PMBus control upstream from point-of-load (POL) dc-dc converters in intermediate-bus-architecture (IBA) power-distribution schemes, Ericsson Power Modules may have sidestepped a patent problem that has all but dried up new IBA developments. The brains are now in the formerly “dumb” bricks that step down 48 V dc to whatever the POLs need. In addition to jumpstarting a stalled digital IBA, Ericsson’s engineers have improved system...

Designers can deliver up to 10 Gbits/s of Ethernet over 30 m of copper cable thanks to a pair of developments from Phyworks Ltd. The 24 AWG twin-ax cable is terminated in SFP+ connector assemblies that employ the company’s PHY2060 active equalizer, CDR, and retimer IC (see the figure). The PHY2060 was originally developed for optical-fiber applications, but it adapts well to the copper...

In recent years, the news of individual battery incidents such as cell-phone and laptop fires has been eclipsed by factory fires and large recalls of lithium-ion (Liion) cells. Several large, well-known Li-ion cell suppliers have been affected. The most notable event was the recall of Sony batteries in 2005. Panasonic and, more recently, LG Chemical have had fires affecting their Li-ion manufacturing volume as well. While these factors present challenges for...

At the recent International Electronics Forum (IEF) in Dubai, UAE, I attended two days of presentations about the semiconductor industry. The speakers were from all parts of the world and offered unique perspectives. But the talk I found most interesting was given by Mark Pinto, CTO and senior vice president at Applied Materials, as his presentation tackled “Energy Conversion: Photovoltaics.” Photovoltaics (PV) have been making great strides in the last...

Last June at Darnell’s Nanopower Forum, Face International demonstrated prototypes of its Lightning remote switching technology for home and business wiring (see “Zombies And Energy Harvesting” at www.electronicdesign.com, ED Online 15788). At that conference, Lightning was essentially a charge stored in clouds of hope. By...

Voltages are bussed around all the time, but the applications and voltage levels are many and diverse. One of the high-voltage apps du jour, for example, is the data center. Everybody knows about the phenomenal rise of the Internet over the last few years, but few think much about how all of the generated data gets stored and distributed. To enable this capability, the emergence and growth of datacenters or server farms—and the power they increasingly...

Recently, a guy asked me how to draw a constant 1.00 mA from a node of a circuit. Of course, he did not tell me what volts, ohms, or frequency. But, he admitted, he basically did not know how to design a current source. So I’m sorry to waste the time of all you guys who do know how to design a current-source. But maybe this lecture can help and save you some time so you don’t have to teach all the young kids. If you need a current source, and you don’t know ...

How does a chip company maximize return on its non-recurring engineering investment? It could duplicate its intellectual property (IP) in a range of ICs aimed at similar applications, but with different feature sets tailored to those apps. Or, it can put the same IP into a narrower range of more versatile ICs. Linear Technology saw that a certain class of its customers had intrinsically similar needs, but a wide variety of what were essentially I/O...

Using the ac powerline at home to interconnect PCs, peripherals, and consumer electronics via broadband techniques isn’t new. Several companies still make powerline modems. However, the wireless approach to home networking using Wi-Fi has become the most widespread networking option. It’s fast and convenient, and it doesn’t require any new wires. But you can also say that about the other home networking options. MoCA uses the installed base coax cable in a home,...

HELLO BOB, A note concerning electric cars and plugin hybrids: Consider that politics has little to do with engineering and/or science. It only pays lip service at those altars. So, somebody has to do serious planning for the immediate future. I’ve been working on some serious battery-charger designs. One of our planners (an engineer) did some research in good old California. We learned that your utility companies have ...

I recently had a chance to visit Odyne Corp., a sevenyear- old company based in Haupauge, N. Y. It develops plug-in hybrid electric power trains for medium and heavy-duty vehicles. While I was there, I met with its director of engineering, Dana DeMeo. I had worked with Dana when he was in college. His expertise then was in repairing all sorts of electronics equipment for his college buddies. Now, he’s in charge of developing the embedded system that controls the...