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Articles from 2003 In March

A Real Steel

The road from rapid prototyping to rapid manufacturing seems more like a highway nowadays. More and more companies have started to produce metal tooling components and even some finished parts on solid imaging systems once consigned to prototyping duties. But the widespread adoption of "digital manufacturing" technologies still depends on the development of materials that can match—or even outperform—traditional machined metals. 3D Systems ( has been doing its part lately with a collection of metals for its selective laser sintering (SLS) machines.

Working directly from CAD files, these machines create parts from layers of sintered metal or thermoplastic powders. On the metals side, the company has recently come out with a new material that can serve as a stand-in for P-20 tool steel. Called LaserForm ST-200, this new material starts out as a 420-stainless steel powder. After sintering on the SLS machine, ST-200 parts go through an oven processing step which infiltrates the steel with bronze, creating fully dense parts. Mark Kosek, 3D's business development manager for tooling and casting, likens it to a "stainless steel sponge filled with bronze." The resulting parts consist of 56% stainless steel and 44% bronze for a final density around 6.73 g/cm³. This steel-and-bronze matrix material exhibits a tensile strength of 435 MPa, a tensile yield strength of 250 MPa, a compressive yield strength of 277 MPa, and elongation of 6%.

The main property differences with P-20 relates to hardness and thermal conductivity. ST-200 measures 79 on the Rockwell B scale, significantly softer than the Rockwell C hardnesses of ordinary P-20 steels. "But the availability of softer steel can be an advantage for those interested in more fast finishing," notes Mervyn Rudgley, 3D's senior director of product management. And Kosek notes that, softer or not, ST-200 has already proved itself in real tools—in part, he says, because the matrix material has good impact properties. He cites a recent customer trial, for example, in which ST-200 inserts, slides, and rails for an injection mold showed no visible signs of wear after 40,000 shots of a 30% glass-filled nylon.

The thermal conductivity of ST-200, at 39 W/m8C, exceeds that of ordinary P-20—a characteristic that Kosek says can ultimately improve the molding productivity by cutting the cooling component of cycle times.

Easy UseST-200 isn't the first tool steel 3D Systems has offered. In fact, at first glance, this new steel seems to fall short of its predecessor, LaserForm ST-100, which actually offers higher mechanical properties and faster build times. But ST-200 has a couple of characteristics that should give it an edge over its forerunner: For one, ST-200 produces parts with roughly 50% more strength coming off the machine. For another, the material development went hand in hand with hardware and software enhancements that improve the overall resolution of the SLS system.

Together these changes make it easier to tackle parts with difficult geometries—such as delicate protruding features, sharp edges, or long thin sections. ST-100 has handled its share of challenging geometry in the past, but it did so with lower yields on the toughest jobs. Or as Kosek puts it, ST-200 makes "difficult geometry more buildable and more survivable." The extra green strength decreases the chance of breakage as the parts make their way through the oven and also allows the parts to withstand more aggressive removal of powder residue with a blast of air. "You can now be quite vigorous with the compressed air," Rudgley says. This last advantage is hardly trivial. Kosek notes that the core and cavity sets for advanced injection molds can have interior cooling passageways that easily trap powder residue. This ability to remove that powder can ultimately increase tooling productivity by enabling conformal cooling passages—ones that closely follow the contours of the molded part to increase heat transfer.

For all the material's promise in tooling applications, ST-200 also supports the move into metal part production. "More than 50% of our ST-100 customers already make as many finished parts as tooling components," Rudgley reports. And he points out that these finished metal components tend to have the very sort of delicate features that ST-200 targets. "Some users shied away from jobs that pushed the envelope on geometry," he says. "Now, they'll be able to tackle these jobs."

More Metals Coming

3D Systems has set its sights on producing other useful metals for tooling and finished components. The first one, due out early this year, closely approximates A6 tool steel. "This material gets us well into the Rockwell C range," Rudgley reports. It's intended for those applications in which maximum longevity and durability outweigh any benefit from faster finishing. And 3D Systems also has its first aluminum slated for introduction later this year. "That one will be really big," Rudgley predicts.

We Know Who You Are

We Know Who You Are

In order for an electronic component to gain a strong foothold in the lucrative million-unit market of consumer electronics, it has to be small, unobtrusive and inexpensive. Until recently, these simple and unassailable parameters have prevented cell phone and PDA manufacturers from adding security ID devices to their products. Fingerprint Identification technology has been too cumbersome, unattractive and expensive.

But Fujitsu Microelectronics America Inc. (San Jose, CA) has broken both the size and price barriers with its MBF 300 Fingerprint SweepSensor, and it has been rewarded for its effort by having been chosen "Best Product of the Year" from the readers of Design News.

The SweepSensor is a capacitive sensor that is composed of a two-dimensional array of metal electrodes, each acting as one plate of a capacitor. The finger acts as the second plate. As the finger is swept across the sensor surface, the unique contours of the skin produce varying capacitor values across the array. The resulting discharge voltages are read, forming an accurate image of the fingerprint.

While security-oriented products have gained increased attention since the 9/11 attacks, the Fujitsu SweepSensor was not designed as a sophisticated high-tech ID control mechanism. Instead, Fujitsu aimed for the high-volume, low-cost consumer electronics market-the highly cost-competitive world of cell phones and PDAs. "The most important challenge the MBF 300 solves in fingerprint recognition is size and cost," says Doug McArthur, director of the Biometric Sensor Product Group at Fujitsu.

According to McArthur, sweep sensor development that grabs an image from just the tip of the finger has helped to break the size barrier. The small size also helps Fujitsu transcend the price hurdle-for cell phones and PDAs, that means below $10. "Until sweep technology, you were stuck with capturing a full fingerprint on a large plate of silicon sensor, and silicon sensors as big as your thumb are expensive."

With high volume consumer products, silicon equals cost. "In the silicon market, they try to make the sensor as small as possible because it has a direct effect on the cost," says Prianka Chopra, analyst at Frost & Sullivan Inc. (San Antonio, Texas). "So companies are trying to reduce the amount of silicon, and the sweep is the way to do it because the area is large enough to capture just the top portion of the finger, about one-fifth of the finger." The actual size of the sensor on the MBF SweepSensor is 1.28 x 0.2 cm, considerably smaller than earlier models with sensors averaging 1.28 x 1.5 cm.

The cost reduction breaks the $10 barrier that precluded the use of fingerprint ID technology on low-cost, high-volume consumer products. "The Fujitsu sensor is $8 to $10 per unit in a quantity of 1,000," says Chopra. She notes that full-fingerprint sensors remain in the $20 to $30 range, so the ability to grab and identify just a portion of the fingerprint suddenly brings a previously expensive technology into consumer product consideration. "The cost of a cell phone is under $100, so how much more can you add to the cost before consumers quit buying?" asks Chopra.

Targeting High-Volume Apps

Fujitsu is clearly targeting the high-volume consumer market and the company is seeking the coveted design wins that ensure the component becomes part of the product. With cell phones, in particular, this translates into big orders. "With cell phones it's always in millions-per-month," explains McArthur. The turnaround from component introduction to the delivered finished consumer products takes roughly a year, so the Fujitsu SweepSensor, introduced in March 2002, will soon begin appearing on phones and PDAs.

Reducing the size of the sensor area delivers more than just cost advantages for Fujitsu. The minute size of the MBF SweepSensor means that it's possible to attach it to a product that competes to be small. Putting a sensor the size of your thumb on a tiny PDA or cell phone is not a pretty sight. "Now it's small enough to fit on the back panel and not look really ugly," says McArthur.

The small sensor array also allows for more control-area room on the device. "The array is no longer the dominant area of the chip, so the control area becomes the dominant area," said McArthur. "With the array only 30 or 40 percent of the chip, the rest is processing, which allows you to add horsepower into the sensor. That opens up the roadmap to more advanced IP-intensive fingerprint ID."

The Design News new product judge, Michael Ruane, picked MBF Fingerprint SweepSensor for its size and its sophistication in biometric sensing. He also likes its low power needs and powerful software drivers. Ruane notes that Fujitsu's product combines a CMOS technology capacitive sweep sensor for converting a fingerprint into a 500 dpi image that yields "minutiae" features that can be matched to stored fingerprint patterns.

Frost & Sullivan's Chopra contends that other companies have also introduced low-cost fingerprint ID technology. "Fujitsu was not the first," said Chopra. "Atmel [Corp., a semiconductor company in San Jose, CA] was actually the first. They use a heat-based sensor." Chopra states, however, that Fujitsu's technology is riding the market drift in low-cost fingerprint ID. "The sweep is definitely the trend in the market." Chopra points out that the Atmel device is getting some traction at HP where it's embedded into new products. She notes that Atmel has also been able to get its sensor under the $10 barrier that opened doors for Fujitsu.

Whatever the potential competition, Ruane believes Fujitsu has a market edge on the low-cost ID market. "I think they'll enjoy a market advantage with this MBF 300," said Ruane. "Fujitsu will have competition in the basic technology, but I see no one at the moment who can offer a competitive, low-power and flexible sensor that also has integrated capture software."



Analog input boards

Simultaneous A/D conversion

The APC341 for desktop PCI and AcPC341 for CompactPCI feature 16 different input channels with a plus or minus 10V dc range, organized in two 8-channel banks. Designed with eight 14-bit A/D converters that can sample channels simultaneously in 125 kHz, the input boards reportedly can sample one million channels per second for a 1 MHz overall throughput rate. The simultaneous scanning also allows for simultaneous comparison of different measurements. Acromag Inc., Enter 679

Magnetic switch

Spherical magnet contact

This magnetic switch provides high-voltage contact welding resistance and magnetic tamper/defeat resistance. According to the company, the switch is the only stand-alone ferrous proximity sensor. It features a hermetically sealed steel construction and spherical magnet contact. The magnetic switch may be used in most markets, including security applications replacing door and window sensors. Magnasphere Enter 680

Relays and optocouplers

Wide voltage range

The Series 859 rail-mounted switching relay terminal blocks and optocoupler terminal blocks are designed with the Cage Clamp Compact spring pressure termination technology and made to accept 22-14 AWG. Available with input voltages of 5, 24, 48, 60, 115, and 170V dc, the relays and optocouplers reportedly may combine different voltages and old circuitry with current industrial control systems. They feature a 6-mm wide housing, five connection points, built-in test points, and custom circuit marking capability. WAGO Corp., Enter 681

Instrumentation modules

Channel-to-channel isolation

The DI-1000TC line of instrumentation modules is designed for use across all temperature-measurement applications including laboratories and heavy industry. Its channel-to-channel isolation feature is designed for use in industrial applications that include the large common-mode voltages typical of grounded thermocouples. They also support synchronization of measurements among connected modules, guaranteeing simultaneous readings. Features include sampling rate of 5 Hz, free PDA software, built-in open T/C detection and high accuracy. Dataq Instruments, Enter 682

Spring clamp terminal block

Expands circuit design options

The ZSRK2.5 Series panel mount mini spring clamp terminal block is available as a 5-mm width block that allows voltage to be distributed throughout a multipole assembly. Made with a top wire entry design, it features individual snap-together elements or multipole assemblies up to 12 poles. Applications include wire terminations in confined space uses, as in panels, small enclosures, and equipment and machinery housings. Conta-Clip Inc., Enter 683

Inverter driver ICs

Simplifies motor drive design

Appliance manufacturers using variable speed motors can reportedly save half the energy and use new features with the IR2136 family of three-phase, inverter-driver ICs. This series is designed to save energy in electronically driven home appliances like clothes washers and air conditioners, as well as light industrial and automotive motor drives. Features of the 600V ICs include COMS or LSTTL compatibility and 120 mA/250 mA output source/sink current. This IC uses cross-conduction prevention logic to eliminate short circuits and automatically clears over-current fault conditions. International Enter 684

Cable assemblies

For automotive telematics

IDB IEEE1394 (Intelligent Data Bus) Consumer Convenience Port connectors consist of hot-pluggable cable assemblies and corresponding PCB-mount receptacles. Cable assemblies are available in lengths up to 10m and in four versions: bilingual plug to beta plug, bilingual plug to bilingual plug, bilingual plug to IEEE 1394 AV plug, and bilingual to IEEE 1394-95 plug. The fully shielded right angle PCB-mount socket is designed to withstand 7,500 mating cycles. Lumberg Enter 685

Dc/ac inverter

Powers in-vehicle electrical devices

A 150W dc/ac inverter is available to power in-vehicle electrical devices, like televisions and VCRs. Reportedly the most powerful of its type, the inverter features 300W peak power, low battery warning buzzer, short-circuit protection, shock protection, low key-off current, optional driver-controlled on-off switches, and LED output reader. Applications include portable televisions, VCRs, personal computers and peripherals, and infotainment systems. Designed to meet OEM power and performance requirements, units reportedly help protect appliances from radio interference, electrical fire and other vehicle damage. Omron Automotive Electronics, Enter 686

Digital signal processors

With configurable software control platform

The TDPS1000EVM digital power supply developer's kit features a fully configurable software control platform that includes intelligent fault management, active-in rush control, and digital current sharing, allowing for a single solution to be used across multiple platforms. The DSP kit, based on the company's TMS320C2000 DSP platform, may be used in such applications as telecom switching equipment, high power rectifiers (300W+), network servers, and uninterruptible power supplies. Texas Instruments Inc., Enter 687

Heating blankets

Provide controlled heat-ups

Environmental factors in heating applications require products with the ability to withstand chemicals, moisture and abuse. SRMU silicone rubber heating blankets come in a variety of sizes and shapes, resist radiation, and are a flexible solution for freeze protection, process temperature control and solids melting. As OEM or replacement parts, silicone blankets are reportedly ideal for applications requiring rapid heat up, steady temperature maintenance and uniform heat distribution. OMEGA Engineering, Enter 688

MCR temperature transducers

HART compatible

Adding to the company's family of signal conditioners, these loop-powered MCR temperature transducers come in both a standard head mount version for DIN-B style field installations and a 12.5-mm housing for DIN-rail mounting. Designed with HART compatibility, they convert temperature signals from thermocouples, potentiometers, RTDs, and sensors into 4-20 mA analog signals, powering the signal conversion. Transducers reportedly may be mounted in hazardous areas and feature LED indication for wire break or short circuit diagnostics. Phoenix Contact, Enter 689

FPC connectors

Secure cable retention

Design engineers can make secure PCB connections in hand-held devices using 6298 Series connectors with a space-efficient, very low profile of 0.9 mm. Units feature front-hinged actuators and connectors that lock flex cables into position, compensating for poor cable retention. Available in 3 or 4-position types, these 0.5-mm pitch connectors accept 0.2-mm flex circuits. With an operating temperature range of -25 to 85C, units are surface-mountable and compatible with automated assembly equipment. AVX Corp., Enter 690

Relay and coupler

Ac switching and control components

The company's Solid State Relay (SSR) and Phototriac Coupler features ac switching and control components for appliance, HVAC, industrial and manufacturing equipment markets. The PC2 and PC3 lines of DIP-4 and DIP-6 Phototriac Couplers offer low power and triggering current as low as 3 mA, in addition to noise immunity. The 8-pin DIP SSRs, with both zero-cross and non-zero cross type, are designed for small power requirements. Sharp Microelectronics of the Enter 691

Fiberoptic sensor

For direct surface mounting

A miniature fiberoptic sensor designed to be used without an enclosure does not require DIN-rail mounting and features a unique snap-mount bracket and an adhesive-mounting for location flexibility. Reportedly, rugged, lightweight and low profile, the plastic housing and IP67 environmental rating make units ideal for mounting directly on machines. Designed for use with the company's stainless steel sheathed fiber, the system is less bulky than glass fiberoptics. Features include visible light beam, manual adjustment, and 8-segment LED display. Banner Engineering Enter 692

Screwless wire connector

Alternative to soldering

The BUCHANAN two-position vertical screwless wire connector, the latest addition to the company's line of board mount wire connectors, provides an alternative to soldered, direct wire-to-board terminations. Connector contacts, spaced on 3.5 mm staggered centerlines and providing a 600V ac rating, have a 2A current rating and may be re-terminated up to five times. Applications for the wire connectors include garage door openers, HVAC controls, security systems, lighting products, vending machines, and gaming products. Tyco Electronics Corp., Enter 693

No Fog in Here

No Fog in Here

With the exception of teenagers out on a hot date, most people find steamed up car windows pretty annoying. "Fogged windows consistently rank among the top ten consumer complaints with new cars," notes Tom Urbank, an advanced development engineer at Delphi Automotive Systems. But fog problems no longer steam Urbank. Working with Delphi's Electronics Integration Team, he and Sensor Development Engineer Tim King have developed a system to automatically counteract fogging.

It's not the only automatic fog fighting system on the market. European cars have had them for a couple of years, and Delphi itself has systems in production for Renault. But there's still plenty of room for innovation. Previous systems either detect fog with optical sensors or use environmental measurements to infer fogging conditions. Urbank faults both methods. "Optical sensors only detect fog once it's begun to form," he says. "And inference methods have too many variables to accurately predict fogging."

Delphi's new automatic fog control system differs from these approaches in some important ways. For one, it cleverly integrates a custom dew point and glass temperature sensor into existing automotive interiors in a manner that balances the need to sense interior conditions against the obtrusiveness of the sensor itself. For another, its patented control methods allow the system to make pre-emptive strikes against fog.

Fog watcher

Delphi's system begins with a custom two-sided sensor designed by King. Outwardly, it looks like a tiny (20 mm across) hockey puck mounted behind the rear view mirror. Inside, it contains a flex circuit board and three sensors. One measures the glass temperature, and another reads the inside cabin temperature. The third picks up humidity inside the cabin. "We scoured the market for the right sensors, and did a lot of testing," King recalls. Some of the problems included finding a humidity sensor whose response time matched those of the thermistors. Many of the low-end humidity sensors he evaluated took minutes to work rather than seconds required for fog control.

The two thermistors also had to be thermally isolated from one another inside the sensor package-something King accomplished by sandwiching an air gap and flex circuit board between the two temperature sensors. Finally, the sensors had to be chemically resistant to everything from take-out food to suntan lotion and cleaning fluids.

To determine the best location for the sensor, Urbank spent a lot of time in an Oldsmobile "so heavily instrumented that it was ugly," he says. The car allowed him to simulate a variety of fogging conditions-right down to the contribution of the occupants' breath. From that work, Urbank and King identified an optimum sensing location right behind the rear view mirror. There, the sensor can take glass temperature readings directly-avoiding the problem of inferring temperatures from locations further away from the glass. And as an added bonus, many mirrors already have a wiring harness to support sensor power and communications.

Patented algorithm

Once the dew point and glass temperature sensor collects the raw fogging data, Delphi's patented control algorithms take over. "We control fog based on the differential between dew point and glass temperature at all times," Urbank says. To do that, the system first sends the sensor outputs through a serial connection into the existing climate-control microprocessor, which converts the ambient temperature and humidity data into dew point equations.

With these equations in mind and test data from the instrumented car in hand, Urbank ultimately developed linear interpolation tables that reduce windshield temperature and dew point relationships to a single-number that captures the probability of fog formation. This value automatically triggers various fog-fighting countermeasures-like turning on the air conditioner compressor, adjusting blower speeds, and regulating the recirculation vents. "There's a progression of countermeasures," Urbank says.

Contact Tom Urbank, Delphi Harrison Thermal Systems, 200 Upper Mountain Rd., Bldg. 6, Lockport, NY 14094; Tel: (716) 439-2293; or Enter 550;

Simplified Design Keys Manufacturing in China

Simplified Design Keys Manufacturing in China

When Tektronix engineers designed the TDS1000 and 2000 Series Digital Storage Oscilloscopes, they had one goal: develop the world's most affordable scope. And to get the most functionality at the lowest cost, Tektronix took the project to China.

The result: LCD oscilloscopes with up to 200 MHz bandwidth and 2GSamples/sec maximum sample rate with FFT (fast Fourier transform) math functionality.

From conception to product, the entire project took only 14 months. Such an effort required project engineers "to wear a different designer hat," says Jim McGrath, mechanical project leader. Basically, one has to keep three things in mind to manufacture efficiently in China, he notes:

  • Understand supplier capabilities, i.e. fabrication processes.

  • Develop a concurrent design effort with your supply base.

  • Set up a good communication system.

Simplify the design

"In China, labor is not an issue," says McGrath. "They can hire as many people as they want for such low wages that assembly costs are basically nil. Here in the U.S., we tend to design complex part assemblies," with fewer parts and fewer assembly procedures. Components are snap fit in order to reduce the time on assembly line.

"In China, you go back to the basics of designing very simple parts which require many assembly operators," notes McGrath. Take for example a sheet metal part such as a chassis. "If the part were manufactured in the U.S., engineers would design one complicated tool and one press to fabricate that part," he says. "But for China, we break that component into six simpler parts. The fabrication process involves one or two people who stand in front of each of six presses and hand transfer the piece of sheet metal through the process."

Material selection is also critical, notes McGrath. In China, companies use EG (electro galvanized) steel for 90% of their sheet metal needs. In the U.S., engineers primarily choose aluminum because it is lighter weight, more environmentally friendly, and doesn't rust.

"But if we want to use aluminum in China, we would have to import the material," says McGrath. After all the costs were added up, Tektronix found they would have to pay four times the equipment cost to import aluminum. So Tektronix engineers designed the product using materials that the Chinese commonly manufacture.

In addition, "China is still young from a technical standpoint," notes McGrath, "which means we have manufacturing processes that they don't have yet." For example, the Chinese do not have vacuum metalization coating capabilities. "If we have a plastic part, we have to find an alternative solution such as a different kind of paint or a foil adhesive."

Working together

Tektronix has a Global Design Team that developed and now manufactures the scopes. A core of designers, manufacturing and material commodity teams, buyers, marketing, and materials trackers reside in Oregon. The manufacturing site is in Yangzhong, China. And materials and parts came from all over China.

To coordinate such a far-flung team, "It is critical to have a working relationship with your suppliers," says McGrath. "You need to understand their capabilities so you don't design something beyond what they can do. And they need to understand your expectations and what quality means."

To facilitate communication, Tektronix engineers send their electronic Pro/Engineer files via the Internet to a point person in China who coordinates the design process. "It is better to have one person who speaks the language be the focal point," says McGrath. Nancy Kwok, McGrath's commodity manager in Hong Kong, fires off the electronic files to the vendors and when questions come up, she translates them to English and sends them to me."

Pleased with the oscilloscopes' outcome, Tektronix plans on exploring new manufacturing endeavors in China.

Contact Jim McGrath, Tektronix, Inc., 14150 SW Karl Braun Dr., Beaverton, OR 97005, Tel: (503) 627-5570; E-mail: [email protected]; Enter 555;

Get Your Free Samples Here

Get Your Free Samples Here

Electronic component suppliers routinely provide free samples of their latest offerings. While that's a great way to build up future business opportunities, let's face it: The bulk of the business is in the tried and true stuff, some of which has been around for years. Recognizing that fact, Texas Instruments Standard Linear and Logic Semiconductor Group is teaming up with DigiKey to offer engineers fast access to free samples (and free shipping) of some 80% of its 15,000 part numbers at: "We continue to see tremendous demand for many of our mature parts, and most engineers like to get some samples, put them on a board, and try them out in their systems," says Bert Bond, Worldwide Logic Product Manager. One perennial favorite: TI's hex inverter. Possibly the oldest technology in TI Logic's current product line, it just keeps going and going, says Bond. So okay, to be fair, it's not like engineers couldn't get free samples of older parts in the past. But, says Bond, those requests were handled on an exception basis. "It was very cumbersome, and usually took days," says Bond. Now, TI is guaranteeing overnight processing of all sample requests. No exceptions.

Laser Boost

Laser Boost

Osram Opto Semiconductors ( has developed an optical pumped semiconductor (OPS) disk laser prototype that puts out 8W of 980-nm optical power from 19W of pumping power. This is an order of magnitude more efficient than previous semiconductor lasers. One key to success is highly effective heat dissipation of excess energy from the laser's active area. Osram sees this as a major breakthrough toward consumer uses such as laser television displays.

FPGAs Find More Uses, Markets

FPGAs Find More Uses, Markets

The applicability of programmable semiconductors is opening up, thanks to lower prices, more convenient form factors, and expanded capabilities. As the practicalities of the chips increase, so should the universe of product designers considering their use.

To what extent will these engineers switch from the conventional ASICs (application specific integrated circuits) to adopt programmable logic devices (PLDs)? Individual customers will still need to do their homework to make that call.

Field programmable gate array (FPGAs) chips, the most sophisticated type of PLDs, are already finding their way into markets not practical before, including plasma screen televisions, digital set top boxes, and automotive telematics systems. FPGAs are sometimes characterized as chameleon chips because the off-the-shelf devices can be programmed to handle a variety of duties. The chips can be reprogrammed during the product design process and even after deployment to meet changing performance requirements. They can provide differentiation within product lines. This flexibility encourages innovation, can slow product obsolescence, and lower development costs.

FPGAs found their calling in the 1990s among sectors where speed-to-market and operational flexibility could make or break a company. They were particularly welcome in telecommunications , where the devices help manage data transmission on high-end network equipment.

While the limited markets for such devices made the chips pricey, many customers found them worth every penny. Cellular operators, for example, found that the operation and maintenance advantages gained by the ability to modify equipment remotely with software programs provided substantial return on investment even if each application required dozens of the chips costing several thousands of dollars apiece.

Telecom is now stalled, but FPGA vendors claim readiness to serve markets that wouldn't consider the technology before. "They're branching out. It's not to say they haven't done that in the past. You have to look farther afield in different applications to generate new revenue," says Richard Wawrzyniak, senior ASIC and system-on-chip analyst at Semico Research Corp.

FPGAs also offer time-to-market advantages compared to ASICs, which are custom-built for each application. ASICs, on the other hand, can be dirt cheap on a per-unit basis due to high volume production, and they're generally faster, smaller, less power hungry than FPGAs. But ASIC customers rack up exorbitant up-front non-recurring engineering costs-particularly mask charges. FPGAs, made without a mask, don't put that burden on their customers.

BlueArc, a start-up that makes silicon servers, says it could not have designed its products without FPGAs, which it purchased from Altera. Geoff Barrall, executive VP and chief technology officer at BlueArc, says the ASIC development costs were prohibitive despite the fact that the FPGA approach required more chips, at higher per-unit cost than the ASIC alternatives. "For a company in our stage of growth, it doesn't make any sense to be shelling out big amounts of money," he says.

While FPGAs got their start in the 1980s to provide simple "glue logic" functions, today the devices often integrate some system-level functions such as memory, input/output tasks, and processors to achieve both performance and efficiency advantages. Suppliers are working to add on more functions, like digital signal processing.

Some ASIC suppliers themselves have also begun incorporating FPGA capabilities so that the once-unchangeable devices be reprogrammed. IBM, for example, recently licensed a Xilinx FPGA core and will embed the technology in forthcoming ASIC product lines. The move is an "excellent indication of the future importance" placed on high-end embedded FPGA technologies, says Jerry Worchel, a senior semiconductor analyst at In-Stat/MDR.

IBM foresees broad applicability for the products, from networking and IT segments to pervasive computing and consumer products. "This is something fundamentally that was driven by our customers," said Peter Gasperini, manager of IP sourcing and embedded FPGA.

While the respective FPGA and ASIC camps borrow from each other, FPGA makers believe they've already made gains on traditional ASIC advantages in per-unit cost, size, and speed. Both Xilinx and Altera will soon produce FPGAs using a next-generation 90-nm process on 300-mm wafers, keeping pace with the latest ASIC manufacturing trends. The processes will cut chip size by half or more while greatly increasing yields and performance and substantially cutting costs.

Still, not all companies are buying. Motorola, for example, says it does not use FPGAs in its cellular phones because of power consumption and cost. "Certain applications can't tolerate any increase in cost, no matter what benefits are brought to the table. But with lower price points you start looking at applications that are on the fence," Wawrzyniak adds.

As Robert Bielby, senior director of standard solutions marketing at Xilinx sees it, FPGAs will challenge ASICs and customers will switch if the alternative gives them quick results and comparable quality at an equivalent price.

Show Products

Show Products

Flow control systems

Custom engineere

Rapid Control Prototyping Buys Time

Rapid Control Prototyping Buys Time

You're working on a new vehicle powered by a hybrid power plant that links an internal combustion engine with an electric motor. Simulations show the power plant's control algorithms work well, so you're anxious to find out if they'll actually run a linked engine and motor. You wonder if you can get the project moving faster: "Can't we test the algorithms on a computer with cards that monitor the sensors and drive the actuators?" In short, you can: Welcome to rapid control prototyping.

This technique, in which a standard computer temporarily replaces the actual controller, provides a way to rapidly test algorithms during the development of products such as laser printers, home appliances, adaptive cruise controllers, and hybrid-motor controllers. If designers uncover problems with a control algorithm while using a rapid control prototype, they can quickly modify their code and run another test. Often, rapid control prototyping uncovers operating conditions and transient phenomena that designers couldn't account for in initial simulations.

Tempers flaring: Testing evolving algorithms on changing hardware usually leads to shouting matches between the hardware and tsoftware developers. Because neither group can provide a stable product for the other to work with, communications often descend into shouting matches.

Rapid control prototyping also may diminish the battles between the algorithm developers and the controller developers. By testing algorithms independently on real hardware, designers can feed changed requirements to the controller design team without anyone feeling to blame for problems. Rapid control prototyping saves time because the power-plant designers don't have to wait for a complete prototype or breadboard of the final controller before they can test their control algorithms.

In the case of the vehicle described above, the algorithms would act to keep the hybrid power plant operating within limits established by torque curves and other empirical data. Most likely, the power-plant designers obtained this information during earlier, separate testing of the internal-combustion engine and the electric motor. The power-plant control algorithms also may incorporate data from flow charts or state diagrams that indicate, for example, which sensors to check, in what order, and when.

Code Soruce: A controller model supplies the code for a rapid control prototype and also for a final embedded controller that goes into production. The controller code may require a separate compilation, depending on the embedded processor chosen by the hardware-design team.

In most cases, software development takes place on a stand-alone PC and the process includes writing control algorithms and trying them out using simulation software. Designers can use packaged simulation software to develop algorithms or they can use a language such as C or Visual Basic to write algorithms from scratch. During initial testing, the algorithms don't control actuators or obtain data from sensors. Instead, they rely on stored data for "sensor" inputs and they display virtual "actuators" on a computer monitor. By first processing "canned" data and observing the results, the designers obtain a good indication of whether their algorithms work properly.

After determining that the algorithms and timing sequences operate properly, designers can transfer their software to the rapid control prototyping computer that will run the algorithms in real time. To avoid problems, use the same architecture in the development computer and in the rapid control prototype computer. This compatibility helps ensure software from one computer will run on the other. A rapid control prototype computer, though, will need a real-time operating system-instead of Windows-to keep up with the process it's supposed to control.

Unlike the development PC, the rapid control prototype computer must provide the necessary analog and digital I/O boards that will obtain signals from sensors and produce the signals that control actuators. Industrial-grade PCs as well as computers based on PC-104, Compact PCI, VXI, and PXI architectures accommodate a wide variety of digital and analog I/O add-in boards. Commercial simulation software usually comes with a list of compatible hardware that works directly with the software or with algorithms compiled by the simulation software.

As the designers run tests with the rapid prototype computer and tweak their algorithms, they also may change their hardware requirements. They may find, for example, that the control algorithms work well with an 8-bit analog-to-digital converter (ADC) rather than a 10-bit ADC on some sensors. They also may find the addition of two level detectors lets them better control something they didn't think about earlier.

It's unlikely the final controller will use a Windows PC. Instead, the controller design team will choose a low-cost microcontroller to do the job. Either the simulation software must provide code that will compile into instructions that run on the designated microcontroller, or the developers must translate their algorithms into code for the microcontroller. Although the latter task sounds onerous, if the simulation software can translate algorithms into C, the problem becomes manageable.

The design of the final controller still involves hardware and software issues such as using floating-point vs. fixed-point math, handling exceptions and errors, the use of watchdog timers, and so on. Rapid control prototyping doesn't eliminate the task of designing and testing a final controller, but it does let controller development run concurrent with real-time algorithm testing.