Hybrid approach brings COTS to power supplies

Those who build devices to regulate the flow of electricity in sophisticated new military and aerospace systems are discovering that COTS is a hot new commodity that is taking the place of the old standby custom parts.

Sep 1st, 1998
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Those who build devices to regulate the flow of electricity in sophisticated new military and aerospace systems are discovering that COTS is a hot new commodity that is taking the place of the old standby custom parts.

By John Rhea

alue added power supplies" is how Howard Wasserman, president of Lambda Novatronics in Pompano Beach, Fla., describes the growing trend toward hybrid approaches to the design of power supplies for military and high-rel applications. The idea, he explains, is to enable system designers to avoid the high costs of custom designs without locking themselves into standard devices that do not quite meet their needs.

The standard vs. custom controversy, long a feature of the semiconductor industry, was muted in the past for power supplies. The many different voltages, form factors, and other special needs dictated a preference for custom designs despite their greater costs. Now, with the Defense Department demanding commercial off-the-shelf (COTS) solutions, power supply makers are moving toward compromise methods by which the units can be assembled out of a few basic building blocks - often called "bricks" in the business - and tailored to users` needs.

"Standard isn`t going to fly very often because everybody wants to have his cake and eat it too," Wasserman comments. "They embrace the concept but they`re not going to give up on their requirements." He should know. Until recently, Lambda Novatronics sold only custom supplies, and they are used in such platforms as the F-16, F/A-18, and F-22 jet fighters, M1 Abrams tank, and U.S. Navy Arleigh Burke-class destroyer (DDG-51). Company leaders have since moved toward a few standard modules, such as DC-DC converters, high-power modules, and VME power supplies, that can be configured to hundreds of different output voltages. Lambda Novatronics officials offer 11 of these base models, and plan to add five to seven a year, says Brian Haney, marketing manager for standard products.

An example is the company`s new MIL-VME-28 series, a line of conduction-cooled ruggedized COTS 160-watt power supplies with a 6U format that operate from a 28 volt DC input and sell for about $1,500. Users can mix and match the units for a variety of output voltages, and they can also get them quickly. Wasserman estimates that prototypes can be available in three weeks - about the time it takes to negotiate the contract for them.

At ILC Data Device Corp. in Bohemia, N.Y., Mike Pitka, product manager for power devices, is combining standard devices that meet ARINC specifications to create a family of 50-ampere, three-phase motor drives, the PW-82351 for commercial and military aviation and in space. These are typically systems that require a 20-year life, and there is substantial crossover between military and commercial applications. The devices, which cost about $2,000, are going into the Global Express business jet and are being considered for the Joint Strike Fighter. They`re also being used in NASA`s International Space Station and the Defense Department`s Space-Based Infrared System reconnaissance satellites.

The custom designs of the past were either too large or too expensive for today`s applications, Pitka says. "We`re doing what COTS was intended to do," he says. "We make hybrids and reap the benefits of commercial pricing."

Although there is still a need for temperature and radiation specifications, which drive up the cost, ILC experts are using plastic packaging to achieve small sizes and make them compatible with the 1553 databus using a gateway for the interface.

Steve Friedman is in charge of ILC`s remote (solid-state) power controller (RPC) business. He is using bipolar dual in-line ceramic packages for the RP-2100 line of 28-volt DC power controllers, which also are for space applications involving circuit breaker applications. Yet he says he is planning to add plastic packages next year at an estimated initial cost reduction of more than 25 percent and eventually 50 percent when the company is in full production. ILC can screen the parts to customer requirements. Friedman estimates the company is split about 70 percent to 30 percent between standard parts and those customized to user needs.

UTMC of Colorado Springs, Colo., also is supplying 1553 spacecraft databus components and microcontrollers for use in satellite power control systems. The 1553 components, part of the company`s commercial radiation-hardened Summit family, serve as the communication link between the power subsystem and the main satellite control processor to supply health and status information on solar panels and batteries. The microcontrollers manage the power modules.

One application is on the International Space Station, for which Boeing Rocketdyne in Canoga Park, Calif., is building more than 400 power-control modules to be distributed throughout the station to control all aspects of power distribution. These modules use UTMC`s 1553 components, a microcontroller code embedded in an applications specific integrated circuit, logic devices, and static RAMs that UTMC supplies to space-level screening and radiation requirements.

Officials of Clary Corp. in Monrovia, Calif., are also using the "customizable" approach to their line of uninterruptable power supply (UPS) systems for terrestrial applications. The COTS credentials of these devices involve adapting systems originally used in hospitals, police and fire emergency systems, oil fields, and traffic signals to military applications for perimeter control. Any combination of inputs and outputs is available in a 19-inch standard rack, says Richard Henson, Clary`s executive vice president and chief operating officer.

The company is a supplier to system integrators, and the components are the same for a traffic system as they are for a Navy fire-control system, Henson says. Designers at the Naval Undersea Weapons Center are qualifying Clary for deployment of the UPSs in the nuclear submarine fleet. Clary also has secret programs for the National Security Agency, and officials say even they don`t know what the applications are. One of the applications Henson can talk about is a perimeter security system TRW of Redondo Beach, Calif., builds for American embassies. That system was not installed at the embassies in Kenya and Tanzania, which suffered terrorist attacks, and he says "the phone has been ringing off the hook" since the attacks as the State Department tightens up its security measures.

The CT series, which stands for customizable technology, consists of basic building blocks starting at $2,290 for single units that operate continuously and clean up the power by filtering it into pure sine waves, Henson explains. The customer selects the specifications for his system by picking from 16 categories of options, including output power, input voltage, input frequency, input connectors, output voltage, output frequency, communications, software, operating system, bypass options, accessories, and batteries.

Another company taking the value-added approach is Unitrode Corp. of Merrimack, N.H., which is supplying a line of three smart power switches that directly drive resistive or inductive loads to 600 milliamperes in power management and industrial control applications. The added value comes from an integrated circuit that converts a digital input command into a high voltage, high current driver output without the need for external protection circuitry, explains Bill Andreycak, senior product marketing manager for power supply products.

The result is a fully contained, single-chip solution, Andreycak maintains. The UC37 line, introduced last month, consists of two devices for low and high side switch applications and a 14-pin unit capable of both. The technology is the same for industrial, military, and automotive markets, Andreycak says, and Unitrode is also looking at the security and alarm industries.

The new generation of mix-and-match power supplies, configured out of modular "bricks" to customer specifications, is bringing COTS to high-rel applications spanning user requirements literally on land, sea, and air - and increasingly into space. It is more a market niche than a dynamic market like microprocessors or digital signal processors. As one observer put it, there`s no Moore`s Law (the prophecy of Intel chairman Gordon Moore that semiconductor performance will double every 18 months) in power supplies, but it`s a technology that will last as long as electronics does.

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The night-vision system that produced the image above uses the smallest power device K&M makes (inset).

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Clary Corp is introducing a line of customizable uninterruptable power systems with a variety of outpot power options.

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Lambda Novatronics line includes board-level unit

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and customizable building blocks

Bastion of custom designs: K and M

WEST SPRINGFIELD, Mass. - Another company bucking the trend toward hybrids is K and M Electronics, which builds only custom designs and has seen its business shift from 90 percent to 60 percent military since the Defense Department`s stress on the commercial off-the-shelf (COTS) approach to weapons.

K and M officials have optimized a line of power supplies for the night vision goggle business and, even though they are custom designs, they have become essentially a commodity item. One of the company`s major customers is ITT Night Vision in Roanoke, Va., which has been a customer for more than 20 years for helmet- and rifle-mounted applications.

This is about a $2 million-a-year business, and Jim Chase, marketing administration manager at K and M, says prices of the devices supplied to ITT have dropped over the past nine years from $900 to $1,200 to about $300. The night vision market is essentially stable with the two major suppliers being ITT and Litton Electron Devices of Garland, Texas. The K and M power supplies are now as small as 30 to 60 grams.

This is another example of COTS in action, as K and M supplies channel electron multipliers and power supplies to military and commercial OEMs, in each case optimized to the users` needs. The company, a subsidiary of Toronto-based Derlan Industries, makes its own components, including high-voltage, diodes, resistors, capacitors, and transformers. Chase maintains that this capability gives the company its edge. K and M also sells those components to other power supply makers, which Chase says he would not even have considered five years ago.

Although many of the devices are in plastic packages, they meet the full military temperature range of -55 to +125 degrees Celsius. In addition to the night vision units, applications include ruggedized avionics such as power devices for airborne missile warning systems and current efforts to develop commercial aviation versions.

The same technology goes into the company`s commercial and industrial line for computer-aided design, medical instrumentation, and digital film recording. There is even a space application in the CCD camera system of NASA`s Advanced Composition Explorer satellite. - J.R.

`Build them and they will come`: Abbott

LOS ANGELES - One company whose leaders believe they have a better alternative to hybrid power units is Abbott Electronics, which is 100 percent standard products - and 95 percent military.

Officials of Abbott are renaming the company Martek Power Abbott after the French firm Martek Power bought Abbott last May. They contend that they can cut costs drastically by sticking to the standard product approach, and they are on enough military platforms to make a strong case.

"We take the risk. We build them in the hopes somebody will buy," says Megan Daley, marketing coordinator. Instead of the hermetically sealed, space-qualified hybrid power supplies that typically cost $1,000 and more, she says there is a market for Abbott`s line of $200 DC-DC and AC-DC power modules.

The company has evolved with the industry, beginning in 1961 as a totally custom house to produce units compliant with MIL-STD 2000. Yet at the end of the Cold War Abbott leaders found themselves in a volatile marketplace with little or no direction concerning product requirements from the end users in the military.

The commercial off-the-shelf (COTS) initiative, which replaced mil specs with performance specifications, was the signal the company officials we re looking for to transform Abbott into a producer of low-cost, military-grade lines.

Engineers have designed the company`s power modules into such ground systems as the Humvee-mounted improved target acquisition system for mobile targeting of TOW missiles, airborne applications in the cockpit of the AH-64 Apache Long Bow helicopter and commercial aircraft, including the "black box" flight recorder, and at sea with the Ohio-class submarine (SSBN-726) fire control-system for the Trident ballistic missile.

The overall military power supply market is seeing slow yet steady growth, according to Daley. She expects this trend to continue for another five to seven years and believes Abbott can maintain its edge in the low-end niche by underselling the high-end hybrids. - J.R.

Smaller is better: National Semiconductor

SANTA CLARA, Calif. - With mobile applications such as cellular phones and Global Positioning System receivers driving the power module business, scientists at National Semiconductor Corp. in Santa Clara, Calif., are developing a new line of small-outline integrated circuits (SOICs).

These new SOICs will be in dual in-line packages (DIPs) for future devices that use alumina and aluminum nitride hermetic packages. These are smaller than traditional ceramic DIPs, but they meet the requirements of the Defense Department`s Qualified Manufacturing List (QML).

Aluminum nitride versions are particularly attractive for spacecraft and other high-power and high-heat applications, says Larry Dano, an applications engineer at National. These versions offer at least nine times the thermal conductivity of alumina, he says. In the past designers packaged several power devices in TO-3 "cans," which the electronics industry has long abandoned, and the surface-mount configuration eases the task of integrating the devices into systems.

The new line of QML-certified DIPs emulate the Joint Electronic Devices Engineering Committee standard - better known as JEDEC - for plastic widebody (300 mil) SOICs. As such, these devices feature a typical footprint reduction of 37 percent, height reduction of 61 percent, and weight saving of 80 percent over ceramic DIPs.

National`s new SOIC line, introduced early this year, covers the spectrum of operational amplifiers, regulators, and comparators. Designers have integrated National`s switching regulators, for example, into the U.S. Army M2A3 Bradley fighting vehicle and the Air Force`s B-2 bomber. - J.R.

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National Semiconductor Corp. officials are producing QML-qualified power devices in ceramic, surface-mount SOIC packages.

`Bricks` and electrons: Virginia Tech

BLACKSBURG, Va. - Just as the era of very large scale integration (VLSI) revolutionized the digital electronics business, scientists at Virginia Polytechnic Institute and State University in Blacksburg, Va., are trying the apply the approach of ever-accelerating functional density to the power electronics business.

Their goal is to create a standard set of modules formally known as power electronics building blocks, or PEBBs, and colloquially as "bricks." Out of these modules they hope to provide users with a mix-and-match capability to get the maximum amount of power in confined spaces.

Experts at the Office of Naval Research, who are trying to reduce the size, weight, and cost of shipboard power systems, sponsor the PEBB program. The lead organization is the Virginia Power Electronics Center (VPEC) on the Blacksburg campus, which is receiving about $1 million a year to apply VLSI techniques to what has traditionally been the discrete business of power devices.

VPEC director Fred Lee says the custom approaches to power in the past, which resulted in systems with 100 to 200 components, are yielding to hybrid solutions that are driving that number down to 10 to 20. But he cautions that functional integration can go only so far. Unlike the VLSI devices, power systems will still need some discrete components. For example, he says, the magnetic components cannot be integrated.

Moreover, Lee sees a classical chicken-and-egg problem as the technology languishes for lack of sufficient volume, and the lack of advanced technology inhibits greater acceptance. What is necessary, he concedes, is a "killer application" that will accelerate the whole process.

He believes he has found one in the whole field of mobile electronics, such as laptop computers and telecommunications. Yet he has another possibility on his list: motor drives for factories, robotics, and process control. A sleeper may be the heating, ventilating, and air conditioning business, he adds.

The Navy`s interest is in standardizing on an 800-volt DC shipboard power bus to which ship designers can attach several systems with their own power requirements. Since naval vessels must remain in service for many decades, a universal power environment that can accommodate new power requirements driven by the addition of advanced weapon systems would represent substantial potential cost savings.

Nonetheless, one of the first success stories in the PEBB program has been the design of an ultra-low profile (0.18-inch) chip jointly developed at VPEC and Texas Instruments in Dallas. This chip is for a demonstration at the U.S. Air Force Avionics Laboratory at Wright-Patterson Air Force Base, Ohio, of an advanced airborne power supply with a power density of more than 50 watts per cubic inch. This is just the starting point. What the military really wants are densities exceeding 100 watts per cubic inch, adds Jason Lai, a researcher at the center.

As elsewhere in power electronics, there is a commercial off-the-shelf (COTS) connection here too. Virginia Tech`s PEBB project parallels a 10-year effort under National Science Foundation sponsorship and known as the Integrated Power Electronics Modules (IPEM) program. IPEM aims at commercial applications and also uses VLSI as its model.

"Our vision is to create a [new electronics] market through improved functionality, all done through integration and transparent to the user," Lee says. The key to success is getting the technology into the hands of industry by focusing on the manufacturability issue.

The process has been slow, but in true Silicon Valley fashion there is already an industrial spinoff adjacent to the Virginia Tech campus: Virginia Power Technologies Inc.

Dan Sable, president of the spinoff, is aiming at a few standard COTS designs for the 28-volt aircraft market featuring greater efficiencies and better shielding against electromagnetic interference. This remains a small but stable market, but it could grow dramatically if the spacecraft OEMs would adopt a comparable standard.

"It will never happen," Sable says. "Every customer wants its own bus voltage." They also want their won interfaces and screening, he adds, which remains an obstacle to standard parts. - J.R.

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Texas Instruments is fabricating an airborne power supply developed with Virginia Tech.

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