Environmental issues continue to highlight the agendas of design strategy meetings. But it’s no longer just about “getting the lead out.” Now the focus is on optimizing energy efficiency in new chip and system designs. Increasingly, the world’s leading companies are acknowledging that power matters. As a result, companies are aggressively making a conscious effort to address tight power budgets and significantly reduce power consumption.
“Things are definitely changing,” says Martin Mason, Actel’s senior director of silicon marketing. “The industry is starting to get religious about environmental issues,” he said, and that includes turning out more power-efficient, smallform- factor devices.
Mason says the electronics industry should be concerned with the watthour (WH), not just the kilowatt hour.
“The watt-hour is a very interesting concept, and we don’t \[as an industry\] pay a lot of attention to it,” he said. “We tend to talk about kilowatt-hours, and that’s important for space heaters and large appliances. But when you start talking about the millions, if not billions, of electronic devices out there that are consuming a watt at a time, a watt-year makes a great deal of sense and it becomes important.” M
ason’s Dell PC has two batteries that consume 48 WH and 53 WH, respectively, for a total capacity of about 100 WH. In normal operation, the computer lasts about two hours on a full charge, so it takes about 50 watts per hour to run. If Mason were to leave his laptop on 24 hours a day, 365 days a year, he’d use 438,000 WH (or 438 kilowatt-hours) of electricity annually. At a cost of 14.33 cents per kilowatt-hour in his home state of California, laptop use alone costs him $62 per year.
In everyday terms, the U.S. Environmental Protection Agency says 11% to 13% of the average American household’s electric bill comes out of consumer electronic product use. The EPA expects that to climb to 18% by 2015. But with more home builders consulting with retailers and custom installers on home technologies, including home networks that are being heavily promoted by the Consumer Electronics Association (CEA), consumer consumption of energy from electronic products could easily top EPA estimates.
Because of the growing demand for portable electronics, market research firm iSuppli expects the worldwide power-management semiconductor market to expand significantly during the next few years—from $24.98 billion in 2006 to $39.9 billion in 2011. Semiconductors in this segment include voltage regulators, power-management application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), rectifiers, thyristors, and power transistors.
“What we need to do as an industry,” says Mason, “is to come up with smart ways to power our products down when there’s no load involved.” Consumers seem to agree. A recent study of U.S. consumers by research firm Forrester Research found that 12% are willing to spend more for electronic products that use less energy or employ an environmentally conscious design.
In fact, standby power consumption has already begun to decrease. That’s due, in large part, to the success of voluntary government-industry programs such as Energy Star, coupled with technological innovation.
Mason would like to see the EPA establish industry standards for semiconductor power consumption under the Energy Star label. “It would help educate consumers on the impact of the products they’re buying with an industry-wide program,” he says, noting that Actel has already discussed this idea with Energy Star offices in the San Francisco area.
What power savings are possible? LCDs in portable devices are a good example, consuming up to 50% of the application’s power budget. Actel says its new IGLOO video demo board, LCD adaptor board with LCD panels, and video demo kits consume as little as 5 µW while retaining the contents of the system memory and data registers.
As a result, the flash-based IGLOO field-programmable gate array (FPGA) can enable both the LCD panel and controller to function in a power-saving mode and the LCD data and backlighting to be disabled. This creates a significant battery savings for LCD applications.
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Fujitsu Ltd. added several initiatives to its existing environmental program, ranging from using sensor technology for environmental monitoring to specifying materials for IC manufacturing that are renewable, or that require less power, and improving the efficiency of its product distribution.
Besides going virtually lead-free, Fujitsu says that by using its 90-nm CMOS process technology, it has been able to improve power usage by 60%, contributing indirectly to the environment. Fujitsu also has reduced the material in its read/write, nonvolatile dielectric memory cell by 45%.
Demand for chips packaged in tapes has expanded because customers want to mount ICs at higher speeds. However, this requirement can generate large volumes of waste tape after the mounting process. Fujitsu has developed an anti-static embossed tape for chips that is strong and has high dimensional accuracy. This tape, which Fujitsu calls GreenPlaR, is made from corn and is used for packaging major products like mobile-phone ICs.
Fujitsu says it also has developed a plastic based on poly-lactic acid that is flame-, thermal-, and impact-resistant with good formability. The plastic is used in parts of Fujitsu’s notebook computers, including connector covers.
Four of Fujitsu Computer Systems’ laptop computers now comply with the stricter Energy Star 4.0 guidelines. These new regulations are designed to reduce energy consumption.
Fujitsu has also developed classifications for “green” and so-called “Super Green” products that meet at least 90% of the criteria in the company’s internal product environmental assessment checklist, as well as comply with global environmental requirements. Until now, most of Fujitsu’s “green products” in chips have been for particular customers, provided under nondisclosure and proprietary agreements.
Analog Devices also says most of its work in new material development is proprietary—at least for the moment. But ADI has talked about changing many of its parts from epoxy/plastic packages to a halogen- free composition. And like its competitors, ADI is developing new parts that reduce both supply voltage and current. ADI says its designers use the same parts even for line-powered products, reducing power usage across the board.
Other chip makers are moving in the same direction. Texas Instruments recently introduced a floating-point digital signal controller starter kit designed to speed development for greener industrial applications. TI says its new F2833x devices enable variable-speed alternating-current drives, using one-eighth the energy of their constant-speed counterparts. The devices also enable clean energy through solar power inverters that more efficiently convert energy from photovoltaic panels.
Another example is Intel’s QuickAssist Integrated Accelerator for cryptography. Codenamed Tolapai, the system-on-achip (SoC) significantly improves powerefficient performance and form factor—up to a 20% reduction in power from previous multi-component security solutions in the embedded and communications market segments. The Tolapai will be available this year. Intel plans to deliver devices in other market sectors with substantial improvements in power savings using nonvolatile memory technology in 2008.
Intel also is introducing halogen-free packaging technology for its processor and chip-set products this year. The company will convert all of its 45-nm processor and 65-nm chip-set products to halogenfree packaging technology by the end of 2008. The packaging technology for Intel’s 45-nm high-k metal gate family of processors uses a copper column “bump” and a tin-silver-copper solder alloy to replace the previously used lead-tin solder to attach the silicon die to the package substrate (Figure 1 and Figure 2).
The company says developing halogen- free technology required extensive collaboration with its suppliers to ensure performance and reliability goals with replacement materials. The first to make the conversation will be Intel’s “Menlow” platform for mobile Internet devices.
Chip size matters too, though it can be deceptive. “Shrinking die and improving yields can reduce the total consumption of material,” says Griffin Teggeman, manager of Freescale Semiconductor’s environmentally preferred products program. But smaller chips usually mean more real estate for other devices and more functionality per device. As a result, Teggeman says, “Getting rid of lead has received much more aggressive action because of regulations.”
Other companies are being a little more creative. GreenPlug has come up with a reusable, multiport power supply that can provide a universal power interface for all electronic products. Essentially, GreenPlug says it can convert a universal power source to a device’s specific power requirements. It introduced its first environmentally friendly PC power hub earlier this month at the International Consumer Electronics Show (CES) in Las Vegas (Fig. 3).
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Agilent Technologies produces programmable direct-current power supplies for automatic test equipment (ATE) and bench testing. As test system density has become more critical for test system designers, Agilent has incorporated several new technologies that have improved efficiency and power density.
These developments include reducing component sizes and using synchronous rectification to reduce output diode losses. They also include dynamic down programming (to reduce dissipation during output discharge) and upgrading components with lower charge losses to offset the extra power accrued from higher switching frequencies.
“As new technologies have made the design of our products more challenging, we have increased the use of modeling to predict losses in our system more accurately over a wide range of conditions,” says John Kenny, R&D technology manager at Agilent’s System Products Division. “Bill Hewlett used to say, ‘Build it, test it, fix it, build it, test it, fix it,’ and that’s how you have to design. We have moved almost completely to computer simulation and modeling.”
Kenny says these efforts have driven efficiency from the 40% level of traditional linear high-performance system supplies to as much as 85% on Agilent’s most recent offerings, while improving programming speed, density, and response time over linear supplies. Noise levels, a traditional problem with switching supplies, have been kept to linear levels, 3 to 6 mV p-p.
Agilent’s newer designs use dynamic down programming, which reuses normally lost switching and bias losses. This adds to the amount of power available to rapidly discharge the output capacitor for high system throughput.
DSP-based control and monitoring have also replaced power- and space-hungry analog circuitry with a common set of high-efficiency digital systems that draw less power at all power levels. The DSP circuits replace traditional analog bleeds, which were previously used to stabilize light-lead-loop stability.
Kenny says the two key efficiency issues his customers have are the cost of running tests (electricity) and trying to make the most efficient use of their factories. “For the bulk of our customers, the payoff is that smaller equipment means they can utilize their factory space better,” he says. “For some customers, mainly the smaller ones, the big issue is the amount of energy they’re consuming.”
IN THE BEGINNING
The European Union is currently reviewing its Restrictions on Hazardous Substances (RoHS), which largely kicked off the movement toward non-toxic materials in electronic products. Tweaks in the language of the RoHS legislation are very likely and will be very closely watched by chip manufacturers and OEMs. The EU is expected to clarify some of its current definitions and terms, and it is seeking industry input.