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July 17, 1997 WHAT'S HOT IN THE DESIGN COMMUNITYMotorola embraces Compact PC Citing the complementary, not competitive, nature of VME and Compact PCI (CPCI), Motorola has introduced a family of CPCI boards and systems. The offerings target telecommunications and other applications in which CPCI's density, rear-panel I/O, and high performance are advantages. Motorola will offer the first boards for sampling in August and has scheduled board and system production for October. Motorola's first CPCI board, the MCPCI2600, uses the PowerPC as its core CPU. Bridge chips connect the 64-bit PowerPC bus to the PCI bus and to a 144-bit memory bus. A 1-Mbyte flash block and a memory-expansion mezzanine slot connect to the memory bus. The memory slot can contain 16 to 256 Mbytes of error-corrected DRAM or 4 to 8 Mbytes of flash memory. A level-2 cache connects directly to the CPU. Board prices start at $3995. The board's PCI connection includes a 32-bit external PCI port and 64-bit onboard PCI. A PMC slot and 10/100 Ethernet connect to the PCI bus. A second bridge chip connects the PCI bus to the ISA/IDE bus for PC-compatible I/O ports, including two USB ports. In place of a disk drive, the board includes a 10-Mbyte flash drive. Motorola acknowledges that CPCI may take some of the low-end applications away from VME but sees no significant conflict between the technologies. Rather, it expects each product line to benefit from development efforts on the other, sharing common elements, such as PMC modules. --by Richard A Quinnell Motorola Computer Group, Tempe, AZ. 1-800-759-1107, www.mot.com/computer/. EDN, µC vendors join forces to Twenty-one of the world's leading microcontroller manufacturers have joined to form the EDN Embedded Microprocessor Benchmark Consortium (EEMBC--pronounced "em-bassy"). The group was founded by Markus Levy, EDN's Microprocessor and DSP editor, in an effort to finally kill Dhrystone MIPS as the universal microprocessor benchmark. Dhrystone MIPS' failure is its small size and artificial nature. EEMBC aims to expand the worldwide microprocessor and microcontroller market by creating a standard suite of embedded benchmarks made from real applications. These benchmarks will help engineers evaluate microprocessors and microcontrollers and aid the industry in improving the function and performance of controllers used in embedded applications. Beyond simply creating the test suites and measuring performance using these real-world applications, EEMBC will evaluate performance against such metrics as power consumption, code density, and compilers. The group, containing suppliers of microcontrollers that account for more than 80% of the worldwide microcontroller market, is dedicated to creating an architecturally neutral set of real, usable benchmarks to evaluate controllers. It will release the benchmarks in several phases during 1998. EEMBC is a nonprofit organization with EDN's Levy as chairman; numerous subcommittees will collect and develop the benchmarks. Founding members of the EDN Embedded Microprocessor Benchmark Consortium are AMD, Analog Devices, ARM, DEC, Fujitsu, Hitachi, IBM, LSI Logic, Mitsubishi/VSIS, Motorola, National Semiconductor, NEC, Philips, QED, MIPS Technologies, SGS-Thomson, Siemens, Sun, Texas Instruments, and Toshiba. Motorola, NEC, Hitachi, Texas Instruments, and Mitsubishi are the top five suppliers of microcontrollers and accounted for 56% of microcontroller shipments in 1996, according to In-Stat. EEMBC's charter limits membership to companies that develop and market processors and controllers. The subcommittees can be staffed with engineers from these companies or others that consume processors or develop compilers. EDN's role in EEMBC is as an organizer and facilitator. For further information on EEMBC, contact Levy at markuslevy@aol.com. --Michael Markowitz Power switch uses In many applications, such as slots and ports for USB, PCMCIA, or peripherals, you need to protect against short-circuit or overload faults at the card slot or plug-in port. The 2.7 to 5.5V MAX890L family of P-channel MOSFET switches for high-side switching fills this need without using numerous components or lots of space. The switches in-clude all needed circuitry and let you adjust the current limit via one resistor. The MAX890L comes in an eight-pin SOP and costs $1.25 (1000). It handles loads as great as 1A, and its on-resistance is 0.09 ohms at 3V. A user-supplied low-power resistor lets you set the current limit from maximum value down to 20% of maximum. Response time is 2 µsec--fast enough that transients from plugging in boards and similar sudden-drain conditions don't cause system glitches or resets. A logic-level output signals your system when you exceed the threshold. Other members of the family include lower maximum-load-limit devices, which come in smaller packages, and dual-channel devices in SO-8 packages. --by Bill Schweber Maxim Integrated Products, Sunnyvale, CA. 1-800-998-8800, www.maxim-ic.com. ICs put new spin on motor control IC vendors are offering ICs that simplify electric-motor control and provide better performance. Some vendors are also supporting induction motors for home appliances, in which the brushless motors offer low cost and long life despite their hard-to-control nature. For three-phase variable-speed ac drives, the $3.81 (1000) SA828 waveform generator from GEC Plessey provides the pulse-width-modulated sequences with pro- cessor-controllable waveform shape, frequency, amplitude, and rotational direction. Its output comprises six TTL-level signals to control the switches in the motor-inverter bridge. You can set the carrier frequency, minimum pulse width, and pulse-delay time, or "underlap," to match the turn-on and -off times of the power devices you use in the bridge. The generator stores in internal ROM and then digitally generates the PWM waveform; available waveshapes are sine wave alone or sine wave plus third harmonic, depending on version. The 28-pin, surface-mount or through-hole device provides speed control to as many as 12 bits of accuracy and supports carrier frequencies as high as 24 kHz. The similar, $3.53 (1000) SA838 in a 20-pin package supports single-phase induction mo-tors and provides two TTL-level outputs. SGS-Thomson provides smarts, connectivity, and muscle in an IC for controlling an automotive-door-lock-actuator motor. The L9942 includes an 8-bit ST6 µC core; 4 kbytes of one-time programmable EPROM, which you can replace with mask-programmed ROM; 128 bytes of RAM; a controller-area-network bus-protocol handler and interface; a regulator for deriving the internal 5V supply from an external 12V source; seven switch-contact monitors; and an H-bridge power stage with 4A capacity and 200-Megaohms RDSON. You can program the smart power device to implement desired functions, features, and algorithms and to directly control the actuator motor. The $8.40 (100,000) IC comes in a power SO-36 package with an internal heat dissipator, which has the same footprint as but finer lead pitch than a 20-pin SOIC and that can reside in the actuator case. For implementing ad-vanced DSP-based algorithms for precise servo-motor control, Analog Devices' ADMC300 IC provides fast dynamic response, accurate speed and position control, and smooth torque control over the speed range for open- and closed-loop vector control. The device targets induction, brushless-dc, and permanent-magnet synchronous motors. The IC comes in an 80-pin TQFP and has five analog inputs and A/D converters with 11-to 16-bit resolution. It also offers a 12-bit, three-phase PWM generator; an encoder interface; 12 digital I/O bits; an event timer; auxiliary timers; 4k×24-bit program RAM; 1k×24-bit data RAM; and a 25-MHz, fixed-point DSP core based on the ADSP-2171. You can download an external program ROM with a monitor via the device's serial port; the program ROM also contains motor-control algorithms. A Windows-based code- and algorithm-development system is available for the $9.50 (100,000) IC. The development system works with the International Rectifier (El Segundo, CA) IRPT1056A power model that can drive a 1-hp, three-phase motor. The vendors support their ICs with PC-based development systems and tools and are introducing systems to support existing ICs. Mo-torola, for example, offers an evaluation kit comprising the ITC137 digital motion-control board with an 8-bit MC68HC708MP16 microcontroller and the ITC132 insulated-gate bipolar-transistor power-stage board. The board can drive three-phase, 1-hp motors from a dc bus with voltage as high as 380V. The kit provides for on/off, forward/reverse, and speed control and includes ad-vanced algorithms. The power board can drive dc motors with and without brushes as well as ac induction motors. It also includes current- and temperature-sense and bus-voltage-feedback terminals. You can operate each $375 board in the kit independently of the other as well. --by Bill Schweber Analog Devices Inc, Norwood, MA. 1-617-937-1707, www.analog.com. GEC Plessey Semiconductors, Scotts Valley, CA. 1-408-438-2900, www.gpsemi.com. Motorola Semiconductor Products, Phoenix, AZ. 1-800-521-6274, www.mot.com/sps/general. SGS-Thomson Microelectronics, Lincoln, MA. 1-617-259-0300, www.st.com. I2O breaks PC I/O bottleneck Now that CPUs are fast, and memories are big and cheap, the remaining bottleneck in the PC architecture is its I/O structure. The Intelligent I/O (I2O) specification, which Intel developed and the I2O-SIG (Special Interest Group) manages, overcomes that obstacle by placing I/O activity under the control of I/O processors rather than the CPU. The I/O processors communicate to the CPU over the PCI bus but insulate the CPU from much I/O activity. They handle the hardware-specific drivers, offer peer-to-peer communications to offload some data transfers from the PCI bus, and handle some I/O-processing tasks, such as data compression. The I2O-SIG's release of the I2O Specification 1.5 in March unleashed a flood of I2O products. For example, Cyclone Microsystems began shipping in May a line of Compact PCI boards that use Intel's i960RP/RD as the I/O processors. Prices start at $590. PLX Technology offers a bus-master PCI interface that provides I2O messaging. The company also offers I2O Manager software for both the i960 and the PowerPC 401GF processors as well as a software developer's kit ($495). The most recent I2O product, IxWorks, comes from Wind River Systems. The operating system brings the Tornado development-tool suite to bear on I2O design. Intel ships IxWorks with every i960RD/RP processor that the company sells. In addition to handling all the tasks that the I2O specification requires, IxWorks simplifies device-driver development by offering designers a "fill-in-the-blanks" approach. The developer simply supplies a group of functions that correspond to all the events that might occur in the driver. The IxWorks system uses I/O events to set priorities and dispatch calls to the functions. I2O-SIG designed I2O to speed the PC's handling of data-intensive tasks, such as video, audio, 3-D graphics, and network transactions. Using I2O will help boost the transaction efficiency of servers and workstations. --by Richard A Quinnell Cyclone Microsystems, New Haven, CT. 1-203-786-5536, www.cyclone-com. Intel Corp, Chandler, AZ. 1-602-554-8080, www.intel.com. PLX Technology, Sunnyvale, CA. 1-408-774-9060, fax 1-408-774-2169, www.plxtech.com. Wind River Systems, Alameda, CA. 1-510-748-4100, fax 1-510-749-2010, www.wrs.com. Power-supply-controller IC Switched-mode power supplies and dc/dc converters need an isolated feedback path to control the PWM cycle, which in turn requires either a special transformer winding or an optocoupler device (see "Linear supplies feel the (lack of) heat from switchers in low-wattage applications," EDN, June 5, 1997, pg 73). The TPS5942 from Texas Instruments reduces parts count by incorporating a current-mode PWM controller, an optocoupler, and a voltage reference in a 16-pin package with gull-wing or through-hole leads. Start-up current for the controller is less than 100 µA, and maximum operating frequency is 1 MHz. It can operate from 10 to 30V supplies and provides peak-withstand voltage as high as 7500V. The output of the TPS4942 can drive loads as high as 2000 pF with rise and fall times of 25 nsec. It costs $0.90 (1000). --by Bill Schweber Texas Instruments Inc, Dallas, TX. 1-800-477-8924, ext 4500, www.ti.com. Distributed
data-acquisition Keithley Instruments describes its family of µP-based SmartLink distributed data-acquisition modules as ground-breaking products. Now, that description is true literally as well as figuratively. The latest additions to the line of 1.1×1.3×6.7-in. modules use a new form of high-accuracy, high-voltage, analog-signal isolation to break ground loops. The magnetic-isolation technique achieves 120-dB CMRR from dc to 60 Hz (100 ohm imbalance). Accuracy is consistent with ADC resolutions of 16 to 20 bits. The isolated, 1.1×1.3×6.7-in. SmartLink modules continuously withstand 1500V dc or peak ac between their inputs and outputs. Multichannel modules use an unusual form of analog multiplexer ahead of the signal isolator. Each multiplexer element comprises a T configuration of optically isolated MOSFET-like switches. In the off state, a multiplexer element continuously withstands 400V dc or peak ac with respect to the floating common (the terminal that is common with one terminal of each of the module's input-terminal pairs). One type of module lets you intermix measurements of 20-mV to 40V (full-scale) voltages and 200 ohm to 200-Megaohm (full-scale) resistances. Modules that measure low-level voltages include thermocouple cold-junction compensation and provide linearity compensation for types J, K, T, R, S, B, and E thermocouples. Per-channel prices start at $195 for a six-channel unit. In addition, you can now obtain SmartLink modules with a 12-Mbps USB interface that allows data transmission faster than 500,000 readings/sec. The company adds USB to a list of interfaces including Ethernet, RS-232C, RS-422, and RS-485. Despite the complexity of the USB interface, USB versions of SmartLink modules carry the same prices as those of units with the same input circuits but different bus interfaces. The company supplies drivers that allow plug-and-play operation and hot-swapping of the modules. --by Dan Strassberg Keithley Instruments, Cleveland, OH. 1-888-534-8453, 1-216-248-0400, fax 1-216-248-6168, product_info@keithley.com, www.keithley.com. Application-specific op amps Op amps proliferate like insects and with nearly as many variations to meet the needs of the target applications. The LT2078 and LT2178 op amps from Linear Technology with 70-µV input offset voltage put two devices in an SO-8 package and combine low supply current, dc precision, and low supply voltage for battery-powered instrumentation. The LT2078 features 50-µA maximum supply current per amplifier, 250-pA input offset current, 4-pA p-p current noise, and 200-kHz gain bandwidth. The LT2178's corresponding figures are 17 µA, 250 pA, 2.5 pA, and 85 kHz, respectively. Both devices operate from supplies as low as 2.3V for use with a lithium cell or a pair of NiCd cells and have outputs that can swing to ground while sinking current, thus eliminating the need for power-wasting pulldown resistors. The LT2078 costs $3.50, and the LT2178 costs $3.70 (1000). For professional-level video applications, the Analog Devices AD8055 single- and AD8056 dual-channel voltage-feedback op amps provide 300-MHz bandwidth at gain of 1, 1400V/µsec slew rate, and 60-mA output drive. Differential gain and phase errors are 0.01% and 0.02°, respectively, with 0.1-dB gain flatness to 40 MHz. Among the packaging options are eight-pin DIPs and SOICs as well as five-pin SOT-25s for the $1.29 (1000) AD8055 and eight-pin µSOICs for the $1.60 (1000) AD8056. Also for professional-video applications but with current rather than voltage feedback, Maxim's MAX4223 through MAX4228 family of op amps has 3-dB bandwidth of 1 GHz plus a low-power shutdown mode that puts the output into a 100-kiloohm high-impedance state, which is useful for multiplexing. Slew rate for these devices, which differ in their optimized gain values and their availability in single and dual versions, is 1700V/µsec with differential gain and phase errors of 0.01% and 0.02°, respectively, and 0.1% gain flatness to 300 MHz. The op amps operate with supplies of ±2.85 to ±5.5V, provide output current as high as 80 mA, and are available in six-lead SOT23s for the basic $2.15 (1000) single-channel device as well as other packages. For low-power, low-voltage applications, the OPA336 series of op amps from Burr-Brown operates as low as 2.3V with a 20-µA amplifier quiescent-supply current and offers 125-µV offset. Output is rail-to-rail with 3 mV of the supply and a 100-kiloohm load. These 5.5V CMOS devices also feature 1-pA input bias current and 115-dB open-loop gain. They are available in single-, dual-, and quad-channel versions with similar specifications; prices begin at $1.43 (1000) for the single-channel device. --by Bill Schweber Analog Devices Inc, Norwood, MA. 1-617-937-1428, www.analog.com. Burr-Brown Corp, Tucson, AZ. 1-520-746-1111, www.burr-brown.com. Linear Technology Corp, Milpitas, CA. 1-408-432-1900, www.linear-tech.com. Maxim Integrated Products, Sunnyvale, CA. 1-408-737-7600, www.maxim-ic.com. New pc-board-design tools Incases, Pacific Numerix, and Mentor Graphics have recently introduced EDA tools covering board reuse and electromagnetic-radiation (EMR) analysis. Incases' version 5.1 of Theda, the company's pc-board-design system, includes board-level, design-variant support. (VeriBest (Boulder, CO) announced a similar capability, Variant Manager, in March for the VeriBest pc-board-design system.) Theda Multiversion lets you develop variations of one design using one pc board or hybrid assembly. You use Multiversion on population, in which you can omit some components if systems do not require them; component substitution, in which versions of a product need components with varying performance levels; and development variations, with which you include future function changes in a design. The tool also supports variants at the component level, as well as chip-on-board assemblies at the die or wire-bond level. Theda Multiversion will be available in fourth quarter for $18,000. Theda 5.1 also supports version 4 0 0 of EDIF. You get the interface, which lets you exchange schematic-design and pc-board-design data among EDA systems, as either a two-way interchange format for Theda Schematic Entry or as bidirectional EDIF flow for the Theda Autoboard pc-board-design software. Both options will be available in the fourth quarter. Incases has also announced en-hancements to EMC-Workbench, its signal-integrity and electromagnetic-compatibility-analysis program, which is now available in a Windows version as well as the Unix version. Workbench now includes a virtual-termination wizard, which lets you add and analyze virtual terminations to eliminate a detected signal-integrity problem. Also, Corcoran, Workbench's radiation-analysis module, now generates 3-D polar plots. Viewing far-field radiation levels at points on a sphere surrounding a radiating object helps you detect EMC problems. EMC-Workbench prices start at $20,000. Also targeting board-level EMR analysis is Pacific Numerix's PCB Radiation, an option to the company's PCB/MCM signal-integrity tool. PCB Radiation includes a parameter extractor and Spice simulator to analyze differential and common-mode radiation and to model current-return paths, including power and ground planes. You use Spice or behavioral models, including IBIS models, for drivers, receivers, and terminators. You can export these models to Emsim, a full-wave 3-D electromagnetic solver, for more accurate or system-level simulations. PCB Radiation also includes an interactive router, which lets you analyze post-routing radiation. The tool provides simulation displays in the time- and frequency-domains. PCB Radiation has a starting price of $15,000. Meanwhile, Mentor Graphics has added Basic and Classic to its Integra Station products. You use Basic for pc-board-layout design having no more than four signal layers, 32 power layers, and 2000 component pins. The stand-alone tool costs $3500, but you can include two optional add-ons, Advanced Technologies and Programmable Post-Processor (PPP). Advanced Technologies lets you specify as many as 255 variations of a design. PPP lets you optimize the tool's output functions for manufacturability. Each add-on costs $3500. Classic costs $14,000 and lets you design boards with 32 signal and 32 power layers. Add-on tools include Advanced Rule ($7000) for designs with complex design rules, Industrial and Consumer ($5000) for designing high-volume boards that have tight EMC specifications; and PPP. --by Jim Lipman Incases, Fort Worth, TX. 1-817-332-7422, fax 1-817-332-9226, www.pad.incases.com. Pacific Numerix, Scottsdale, AZ. 1-602-483-6800, fax 1-602-483-8526, www.pnc.com. Mentor Graphics, Wilsonville, OR. 1-503-685-7000, fax 1-503-685-1202, www.mentorg.com. PLDs have low-end gate arrays in the bull's eye Altera's Flex 6000 family continues the programmable-logic industry's assault on the low-end gate-array market. The first member, the 16,000-gate EPF6016, is now in limited production and costs $22.95 (100) in a 208-lead QFP. By the first half of next year, several Flex 6000 devices will span 10,000 to 24,000 gates in QFP and BGA packages. Altera projects mid-'98 prices for the 5V EPF6016, 3.3V EPF6016A, and 3.3V EPF6024A at $7.50, $7, and $10 (50,000), respectively. Flex 6000 chips eliminate such silicon-intensive features as I/O registers, embedded-memory blocks, and PLLs, which the 8000 and 10K families incorporate. The 6000 family also reduces global interconnect. In exchange, the company has beefed up local interconnect, both between logic blocks and from logic blocks to adjacent I/O pins. The result is a blend of traditional continuous-CPLD and segmented-FPGA routing. Altera claims that, even without I/O registers, the added local interconnect still allows the devices to meet stringent setup-and-hold and clock-to-output delays of PCI and other high-speed buses and that reduced global interconnect doesn't adversely affect pin locking. The company also uses a new 0.5-µm, three-layer-metal process and will move to a 0.3-µm process at year-end. Altera has also shrunk the bond-pad pitch to reduce the probability that the number of package leads rather than the number of gates determines the die size. This phenomenon, called "pad-limiting," affects gate-array cost at submicron lithographies and low gate counts. Altera believes that 40% of gate-array designs with fewer than 50,000 gates are pad-limited and that Flex 6000 products will be price-competitive here. Gate count aside, the less efficient PLD architecture may result your design's requiring more gates than if you implemented it in an FPGA. However, even with equivalent lead-count needs, the less-efficient PLD architecture may result in a higher gate-count requirement than if you implemented the same design in a gate array. --by Brian Dipert Altera Corp, San Jose, CA, 1-408-894-7000, fax 1-408-435-1394, www.altera.com. ScanLogic Corp has developed a USB controller based on a 16-bit RISC engine. The SL11R offers a 3k×16-bit mask ROM and 3k×16-bit SRAM for program storage, an I2C-accessible serial flash ROM for USB-device configuration, interfaces to external memory, and a USB transceiver. The $5.25 device also contains a 3-Mbyte dual-SRAM buffer that can simultaneously receive DMA data and send on the USB port. The company also offers the $3.25 SL11 USB interface controller that can adapt most 8-bit processors to work with the USB. The company supports both devices with a developer's kit containing class drivers, demo software, training, and technical assistance. --by Richard A Quinnell ScanLogic Corp, Bedford, MA. 1-617-276-3901, fax 1-617-275-1758. Heat is on for speed-limit-breaking New programmable-logic-market player DynaChip Corp announced its first-generation DL5000 FPGA product line at the 1997 Design Automation Conference, which took place in June in Anaheim, CA. The 5000-usable-gate DL5256 is in limited production, and the company targets 1250- and 10,000-gate devices for availability in the first quarter of next year. Price of the commercial-temperature, F-speed-bin DL-5256 in a 204-bump SuperBGA package is $390 (one to 24). A 208-bump ceramic PGA package and E (lower) and G (higher) speeds are also available or planned. The family strives to deliver ASIC-level performance in various ways. The 0.8-µm BiCMOS manufacturing process, which IBM Microelectronics (Armonk, NY) developed, is inherently much faster than a full-CMOS alternative, albeit at much higher power consumption. Dedicated routing delivers 200-MHz-level toggle frequency within a region of 12 logic blocks, and differential-sensing-signal active repeaters between regions incur a 1-nsec incremental delay (see "Shattering the programmable-logic speed barrier," EDN, May 22, 1997, pg 36). DL5000 devices also provide a choice of three high-speed I/O protocols: ECL (0 to 5V), positive ECL (5 to 0V), and Gunning transceiver logic (GTL) (+2 to 3V). The I/O registers specify a worst-case 900-psec setup time and 1.8-nsec clock-to-valid data delays. Finally, BGA packaging offers lower impedance than that of QFP with its long bond wires and leads. Although DynaChip calls the chips "FPGAs," they contain several CPLDlike features. The continuous-routing resources promise more predicable timing than that of FPGAs. Also, although DynaChip uses SRAM bits to configure logic and other resources and implements logic blocks as dedicated gates. Each logic block (256 in the DL5256) contains a mix of multiplexer, product-term and arithmetic-tailored circuits, plus two flip-flops, set/reset, and multiple clock options. According to DynaChip, this approach is a better alternative than traditional FPGA look-up-tables or multiplexer-only architectures for high-level design synthesis. The company provides libraries for Exemplar Logic's (Alameda, CA) Galileo and Leonardo, and for Syopsys's (Mountain View, CA) Design Compiler and FPGA Compiler. DynaTool software, which runs on Sun workstations and PCs, handles the back-end map and place-and-route functions. --by Brian Dipert DynaChip Corp, Sunnyvale, CA. 1-408-481-3100, fax 1-408-481-3136, www.dyna.com. Tool simplifies visual-software management The Visual Enabler project-management tool from Softlab aims at large Windows-software-development teams. The tool works closely with Microsoft's Visual Basic, Visual C++, and Visual J++ development environments to simplify software-configuration control. It also works with any source-code-control-compliant development tool. Visual Enabler's version-control mechanism detects check-in and -out of code under development, detects collisions (modifications of the same piece of code), and prompts resolution of such simultaneous changes. The tool also automatically determines relationships among pieces of code, offers a one-button build of software, and supports project branching into different versions of software. The price is $1997. --by Richard A Quinnell Softlab Enabling Technologies, Atlanta, GA. 1-770-668-8811, fax 1-770-668-8712, www.softlabna.com. Aug 12 to 14 Internet Expo, Boston, provides technical, marketing, and management tutorials on Internet products and technologies. The expo offers four conference tracks and hundreds of online exhibits. Registration costs $1595. DCI, Andover, MA. 1-508-470-3880. Aug 20 to 22 Piezoelectric Devices Conference and Exhibition, Kansas City, MO, addresses application, design, and manufacturing. Technology tutorials cover crystals, filters, and oscillators. Electronic Industries Association Components Group, Arling- ton, VA. 1-703-907-7547. References establish solid circuit credibility Within almost any mixed-signal system, you'll find a voltage reference that sets a uniform standard for that system, and the precision and stability of the reference is often a key to high-level system performance. Analog Devices' AD158x three-terminal series references are low-dropout (200-mV) devices in SOT-23 packages, with 2.5, 3.0, 4.096, and 5.0V ratings. The $0.75 (1000) devices do not need an external series resistor to set device current flow, nor do they need a buffer amplifier to source and sink load current. Accuracy is ±0.1%, and drift is 50 ppm/°C; and, unlike shunt references, quiescent current is 65 µA, independent of supply current. The MAX6325 references from Maxim Integrated Products feature low noise and extremely low tempco commensurate with 16-bit applications. The buried-zener devices have typical output noise of 1.5 µV p-p from 0.1 to 10 Hz and maximum drift of 1 ppm/°C. Initial accuracy for these eight-pin devices, available in 2.5, 4.096, and 5V versions, is ±0.02%. Each reference can source or sink at least 15 mA; cost is $6.70 (1000). --by Bill Schweber Analog Devices Inc, Norwood, MA. 1-617-937-1428, fax 1-617-821-4273, www.analog.com. Maxim Integrated Products, Sunnyvale, CA. 1-408-737-7600, fax 1-408-737-7194, www.maxim-ic.com. PLL brings CMOS virtues to 1.1 GHz An all-CMOS dual PLL lets you benefit from the low-power attribute of this technology. The PE3282 from Peregrine Semiconductor Corp provides both 1.1-GHz and 510-MHz PLLs in a 20-pin TSSOP IC that operates from 2.7 to 3.6V, with 6-mA typical current consumption. Speed grades to 1.8 GHz are also available. The CMOS devices have inherent latch-up protection and meet the 2-kV human-body ESD protection model. The dual PLL uses fractional-N architecture, and to reduce the spurs normally associated with this architecture, Peregrine has implemented proprietary techniques that require no end-application tuning or external components. The result is spur suppression greater than 70 dBc. The device costs $2.50 (100,000). --by Bill Schweber Peregrine Semiconductor Corp, San Diego, CA. 1-619-455-0660, fax 1-619-455-0770, www.peregrine-semi.com. |
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