Power Hotspot

Battery ?Fuel Gauges? Few of today's handheld devices incorporate a battery-status ?fuel-gauge? chip. But that will change as handheld devices grow into electronic Swiss Army knives. In fact, we're really going to need fuel-gauge chips that are tied a lot more tightly to the system CPU. Imagine a cell phone that incorporates a still photo and video camera as well as audio-video personal media player functions. It would need a pretty smart fuel gauge, right? It would have...

I was down at an "Arrowfest" in Plano, Texas, a few months ago. We had a little panel session about the future with Bill Klein of Texas Instruments, Arnold Williams from Analog Devices, and myself. Most of the audience agreed with the three of us (and the moderator)—the future will have a lot of analog. When we see that the power-supply drain of a fast processor at 0.09 µm is largely related to the device leakages—which aren't very predictable and can't be...

Fuel cells are electrochemical devices that convert chemical energy into electrical energy. The pressing need for green power and the demand for sustainable power backups has motivated a number of companies to consider fuel cells. When fed with hydrogen derived from a renewable energy source, fuel cells emit zero or very low greenhouse emissions. The micro fuel cell introduces fuel into the cell's anode catalyst layer (Fig. 1). A...

Industry experts predict 20-hour cell-phone and laptop computer operation with a micro fuel cell. Frost & Sullivan predicts that micro fuel cells will power up to 4 million mobile devices by 2008. Micro fuel-cell unit shipments will reach $125.2 million in 2010. Toshiba and Hitachi expect commercial versions this year. Micro fuel cells will open a market for replacement cartridges. Current methanol fuel cells are...

Once commercialized, micro fuel cells promise more backup "green power" at lower costs than competing battery technologies. Batteries, closing in on their performance limit, may fall short in the next generation of powerhungry cell phones, laptops, digital cameras, camcorders, PDAs, and military applications. The task of recharging delineates batteries and micro fuel cells. Users can recharge batteries by supplying them with the appropriate voltage and current. However, users...

Increasingly, computer-based systems employ digital control of power supplies to improve power-management flexibility, maintainability, and reliability. Standardized PMBus commands encourage semiconductor and powersupply manufacturers to develop the appropriate technology to control a power supply's operating parameters, monitor its operation, and perform corrective measures in response to faults or operational warnings. Starting with 45 executable...

PMBus Rocks The System-Power-Management World. Such a headline may seem trite. But not since embedded computer systems moved to the distributed power architecture (DPA) and intermediate bus architecture (IBA) has this arena seen such a change. The change was needed, though. Once DPA and IBA matured, it became apparent that one link was missing—the ability to control, monitor, and maintain the power-management subsystem. The PMBus (power management bus) standard...

Digital power-supply control has certainly captured the attention of the power electronics industry during the last 18 months. It has gone from papers presented in those "catch-all" sessions at power conferences to having its own sessions and even its own conference. What has happened to raise digital power from an interesting student project to an active market segment? Power supplies and microcontrollers are not strangers. Micros have been monitoring and...

Recent announcements of several PMBus-based ICs for digital control of distributed power makes one fact clear: There are two different approaches to controller architecture. On the one hand, controllers are based on high-resolution, high-speed analog-to-digital converters with DSPs in the feedback loop. On the other, controllers employ comparators and hardwired digital proportional-integral-derivative (PID) state-machine filters. Zilker Labs has introduced the first product to use the...

As I said in my last column, I don't mind filling in my tax forms.* I can usually look at the 1040 forms and figure what is happening. If I am normally in a 33% bracket, I can tell that the tax is really at a marginal (incremental) rate of 36.8%, or whatever. But in the AMT, I cannot decipher my marginal rate. I may get the nerve to go in and increment my income by $1000 and see what the real change is. But it would take me a couple of hours, and I'd have to be sure I was not...

The automated external defibrillator (AED) is one example of a medical product that's experiencing extremely fast adoption. These growth rates are due to improvements in the ease of use and to the battery technology that enables mobility and remote use. In the event of an emergency, the battery pack must be a reliable power source. Lithium-ion (Li-ion) cells have the highest energy density by both weight and volume. They offer the most attractive method of portable battery power for many...

Clever design, close attention to human safety issues, and a top man-machine interface make the Philips HeartStart portable home defibrillator one of the hottest medical electronics devices on the market. Although other companies make portable defibrillators (Agilent Technologies, Cardiac Science, Welch Allyn, HeartSine, Defibtech, Medtronic, and Zoll Medical, to name a few), the HeartStart is the first to be available over the counter without a medical prescription. The device is...

How do the various field-programmable gate-array (FPGA) technologies rank with respect to standby power consumption? The three mainstream FPGA approaches significantly vary in static and standby power consumption due to the differences in the configuration technologies employed within the chips ? volatile static RAM cells, reprogrammable flash-based nonvolatile memory cells, and antifuse, metal-to-metal one-time programmable nonvolatile programmable elements (...

Probably the best 2005 development in power is the new PMBus (Power Management Bus) open standard specification. It defines a digital communications protocol for controlling power conversion and management devices. Taking part in this collaboration were power-supply and semiconductor companies such as Artesyn Technologies, Astec/Emerson Network Power, Intersil Corp., Microchip Technology, Summit Microelectronics, Texas Instruments, Volterra Semiconductor, Zilker Labs Inc., and others....

This year's most engaging news came from a briefing by Julian Hayes of Wolfson Microelectronics, Edinburgh, Scotland, in September. Walking through the company's-plant, I saw a flat-screen TV disassembledon an engineer's bench. Wolfson was helping a Chinese customer optimize its use of some of the company's audio chips. The number of subassemblies in the design surprised me. "This doesn't look like a low-margin product designed to sell on price alone at discount outlets," I said. "There's...

Most applications that use power factor correction (PFC) are mandated by regulatory requirements like the IEC1000-3-2 harmonic reduction requirement in force since January 1, 2001. The regulation places certain limits on harmonic currents drawn by power supplies. This, in turn, requires an active PFC circuit. Some low-power, cost-sensitive applications still manage to use a passive PFC circuit. Comprised of only inductors and capacitors, a passive PFC circuit is simple and efficient for...

THERE'S A NEW ENTRY IN THE NON-ISOLATED point-of-load (niPOL) sweepstakes. Linear Technology's 10-A (14-A peak) step-down regulator module incorporates everything except input and output capacitors in a lowprofile (2.8 mm), 15- by 15-mm surfacemount land-grid array package. The module consists of a current-mode controller, ultra-low RDS(ON) FETs with fast switching speed and integrated Schottky diodes, and an inductor. Thanks to its low package profile, it can be mounted on the...

WITH EXPANDED CONTROL CAPABILITIES AND A SHRINKING footprint, Power-One's digital-IBA (intermediate bus architecture) controller goes from a module to a chip—with no change in price. The IBA scheme manages and controls power distribution to individual loads on circuit boards in complex systems. At first glance, the controller-on-a-chip may seem like an incremental development. But with recent announcements concerning PMBus-compliant products and Vicor's factorized power...

The IEEE's 2006 Applied Power Electronics Conference and Exposition (APEC) originally was slated for February in New Orleans. Then hurricane Katrina hit. The conference managers wanted to stay out of the way of relief efforts, so they scrambled and found a new venue. The show and conference now will take place at the Hyatt Regency Hotel in Dallas, March 19-23. Let's say you were already set to go. So, you only have to shift your plans by a month. Now let's say you wanted to go,...

THE POWER SOURCES MANUFACTURERS ASSOCIATION (PSMA) is celebrating its twentieth anniversary by offering hardcopy reprints of a classic text on transformer design for less than a student would have paid for it in college. If you're an EE who got into the design of magnetics in school, you may have used Nathan Grossner's classic Transformers for Electronic Circuits as a text—or you would have if you're in a certain narrow age bracket. The book only came out in 1983,...