Wireless Systems Design

On The Wireless Front

Monroe, New York
Acqiris USA has recently come to market with a 21-slot crate known as the CC121. It enables high-speed digitizer systems to be configured with up to 80 channels in a single, standard, 19-in.-wide, 9U-high instrumentation rack. Deploying a quad-channel digitizer module, the CC121 (at 1-GHz bandwidth) can operate 80 channels at a 1-GSample/s sampling rate. That includes 40 channels at 2 GSamples/s and 20 channels at 4 GSamples/s. This operational capability makes the crate ideal for the data-acquisition systems that require a high number of channels in the smallest possible space. Potential uses of this product include physics, astronomy, automated test equipment, and telecommunications applications in which system size and cost per channel need to be optimized.

The crate's patent-pending cooling system allows installed modules to run at an optimal, safe operating temperature. This aspect ensures a stable, uniform internal operating temperature with minimal variation. As a result, there is less drift in measurement precision and less frequent recalibration. Efficient operation is further provided by EMI shielding, which minimizes the effects of unwanted noise and interference. In addition, high-quality power supplies increase system reliability.

The CC121 crate is compatible with CompactPCI extension interfaces and embedded Pentium processor boards for modular "plug-and-play" applications. A variety of standard interfaces can be used to fully control the CC121 and connect it to any PC. A CompactPCI-PCI bridge connection can be made via copper or fiber-optic cables. In such instances, PCI-bus data-transfer speeds of up to 100 MBps can be achieved. Alternatively, standalone systems can be easily created with the installation of Acqiris' PC502—a 1-GHz, Pentium-based, single-slot controller with a 20-GB hard disk, Ethernet, and Windows-based operating system. The Ethernet port can be used to connect multiple crates together for applications that require more than 80 channels.

In addition to its high channel density, the CC121's single-rack design requires less cabling. The result is simplified installation and maintenance. Further simplification is achieved through the use of a unique rear-access design, which yields access to all system components whenever necessary.

Now available, the CC121 can be purchased for $9990 per unit. Delivery time is four weeks following the receipt of the order. For additional information on this product, go to the Web site: www.acqiris.com.

San Jose, California
Taiyo Yuden (U.S.A.), Inc. has now begun the development and commercialization of module solutions for 5-GHz wireless-LAN (IEEE 802.11a) applications. Until this point, the company has been leveraging the market recognition and high-frequency technology that it obtained through its Bluetooth module research and development. Now, it has formally established a partnership with Resonext Communications, Inc. as the supplier for 802.11a chip sets. As a San Jose-based fabless semiconductor company, Resonext Communications develops complete end-to-end chip-set solutions. Resonext began introducing 802.11a chip sets this past fall.

The chip sets feature the True Zero-IF 5-GHz CMOS radio. This radio was specifically designed for reduced materials cost and low power consumption. It also boasts flexible media access control (MAC) to support differentiation and the evolving IEEE standards. In addition, it supports AccuChannel equalization technology. This technology delivers up to a 32% greater range for all data rates. As a result of this partnership, Taiyo Yuden has now begun developing and commercializing 802.11a modules with the new Resonext chip sets. The IEEE 802.11a wireless LAN operates in the 5-GHz band. It is expected to become widely integrated into various electronic appliances in the coming months.

In addition, Taiyo Yuden has announced that its efforts to develop high-speed wireless components and modules will not be limited to 802.11a technology. Rather, the company will be converging its materials; multi-layer, high-frequency design; and high-density mounting technology for use in the development of various solutions. These solutions will aim to simplify the process of adopting new wireless technology.

For more information on the True Zero-IF 5-GHz CMOS radio, contact Resonext at www.resonext.com. For further details on Taiyo Yuden's ongoing development efforts or for information on its partnership with Resonext, check out the company's Web site at www.taiyo-yuden.com.

Analog Devices, Inc. (ADI) now offers a complete chip-set solution that spans the gap from the digital baseband through the RF power amplifier. It will allow wireless-equipment suppliers to create next-generation handsets for the Enhanced Data Rates for GSM Evolution (EDGE) standard. This standard enables higher-speed data services over the existing GSM/GPRS networks with maximum data rates over 200 kbps. Typically, this speed is three to five times faster than the current GPRS network.

The new platform is based on ADI's Blackfin processor, which provides the signal-processing performance and low power consumption required for advanced portable devices. Blackfin combines best-in-class DSP performance with microcontroller functionality. It also meets the computational demands and power constraints of today's audio, video, and communications applications. In addition to the digital baseband processor, the Blackfin SoftFone for EDGE includes a high-performance, mixed-signal analog baseband chip. This chip boasts integrated power management, an Othello direct-conversion RF transceiver with a polar modulator, and a dual-mode power amplifier.

The Blackfin SoftFone for EDGE Platform offers a number of benefits that are not currently available. This includes a scalable clock speed of up to 247 MHz to implement voice codec, radio-frequency-signal-equalization algorithms, and multimedia processing. It also provides full support of quad-band and Class 12 EGPRS operations. Additional capabilities include peripheral interfaces—such as USB, IR, Secure Digital (SD), and MultiMedia Card (MMC)—and serial and parallel ports for color displays, monochrome displays, and cameras.

ADI's platform is the only solution to offer stereo digital-to-analog converters with sample rates of up to 48 kHz. This feature allows MP3-quality audio playback, game sounds, and ringtones. The Dynamic Power Management feature of the Blackfin processor reduces clock speed and core voltage. It thereby minimizes power consumption when full performance is not needed. The radio section of the platform includes an Othello direct-conversion radio transceiver and the ADL5561 quad-band, dual-mode power amplifier with integrated precision power detection and control. The power amplifier operates in either the GSM/GPRS or EDGE (8PSK) modes. It maintains output power at the correct level with tighter tolerances than alternative power-control methods. This leads to extended battery life and fewer dropped calls for the user. In manufacturing, it results in simpler calibration of the phone.

TTPCom of Cambridge, U.K., has developed the EGPRS protocol-stack software to complement the ADI chip set. This software is currently undergoing infrastructure and operator testing. It supports full multi-slot class 12. In addition, it is compatible with TTPCom's comprehensive applications suite.

For more information on Blackfin, go to www.analog.com.

Royal Philips Electronics has teamed with LogicaCMG to deliver mobile multimedia-messaging technologies to mobile operators. Initially, this OEM umbrella agreement will result in the integration of Philips' Platform4 Media Adapter transcoding engine into LogicaCMG's Multimedia Messaging Service Center (MMSC) product range. At this time, both companies are still exploring opportunities for joint cooperation in other areas. These areas might include multimedia streaming and embedded multimedia technologies for mobile devices. The companies will not limit themselves to these areas, however.

For mobile operators, the joint delivery of the LogicaCMG and Philips technologies will enable interoperability across multiple handsets. It will provide their subscribers with optimal MMS quality of service.

Philips' Platform4 range of solutions is optimized for deploying multimedia services through 2.5G and 3G mobile networks and handsets. The Platform4 Media Adapter is specifically designed to meet the requirements of MMSC vendors and service operators. It offers scalable real-time transcoding, usage tracking, and content protection. It also provides a secure migration path to fully integrated media handling.

For more information on this joint agreement, go to the Philips Web site at www.philips.com.

Grenchen, Switzerland
Micro Crystal has come to market with a 32.768-kHz tuning-fork crystal. Known as the CC7V-T1A, this SMD ceramic package has been specifically designed for miniature industrial and telecom applications. A special crystal manufacturing process is used to achieve its improved electrical characteristics and miniaturized blank size.

This tuning-fork crystal comes supplied in special trays that can accommodate up to 200 crystals per tray. For pick-and-place equipment, the parts are available in 12-mm tape. A 7-in. tape reel, for example, comes with 3000 crystals. A 13-in. reel comes populated with 16,000 crystals.

Specific characteristics of the CC7V-T1A tuning-fork crystal include a load capacitance of 9.0/1.2 pF, a series resistance of 50/70 kohm, and a typical motional capacitance of 3.3 fF. Its static capacitance is 1.2 pF. In addition, the crystal's maximum drive level is 1.0 µW, while its turnover temperature is 25°C ±5°C. All electrical characteristics are specified at 25°C.

The CC7V-T1A tuning-fork crystal has a package height of 0.85 mm. It features high stability and low aging. In addition, its low power consumption and high shock and vibration resistance make it a highly enviable solution. For further details on this product, check out the company's Web site at www.microcrystal.com.

Smyrna, Georgia
Murata Manufacturing Co. Ltd. has now upgraded its noise-suppression component-selection support software to include recommended component search and listing functions. Free distribution of the software—dubbed the Murata EMI Filter Selection Simulator—is currently ongoing.

The new software version provides the recommended chip-ferrite-beads search function. It can also list recommended components that suit specified conditions—as long as the user specifies those conditions. To select the recommended components, the software uses signal-waveform quality and voltage spectrum calculation results. With this new function, the user can easily select the chip ferrite beads that are suitable for an application. They can then quickly review the noise-suppressing measures.

The new software can be downloaded free of charge from Murata's Web site at www.murata.com/emi/. It is also contained in the revised version of the company's CD-ROM catalog, which is now available.

For noise-suppression purposes, ferrite beads can be mounted to transmission lines. However, their noise-suppressing effect and influence on signal waveforms both vary according to the inherent impedance and length of such transmission lines. In order to maintain an excellent signal-waveform quality while improving the noise-suppressing effect, one must select the ferrite beads that are most suitable for the transmission-line conditions. Generally, for this purpose, the engineer relies either on experience or the use of a "cut-and-try" process by mounting sample components. The EMI Filter Selection Simulator software deals with this problem head-on by simplifying the component-selection process at the circuit-design stage.

When selecting noise-suppression components with the conventional version of this software, however, engineers still needed a certain level of knowledge of the components. With the upgraded software version, this is no longer the case. The software now provides the function for finding and listing the ferrite beads that are most suitable for noise suppression under user-specified evaluation criteria. As a result, users can select ferrite beads easily and quickly. A future revision of the software also will offer this search and listing function for capacitor-type EMI filters.

For more information on the EMI Filter Selection Simulator software, go to www.murata.com.

Sunnyvale, California
Maxim Integrated Products has recently introduced the MAX2045/MAX2046/
MAX2047 family of highly integrated vector multipliers. The MAX204x family is specifically designed for the demanding requirements of GSM/DCS/PCS/EDGE, iDEN, PHS, CDMA, and 3G linearized power amplifiers for cellular base stations.

These devices have a 12-dB gain-control range and a 360° phase-control range. Gain and phase-flatness performance yield ±0.25 dB and ±0.25°, respectively. The constant group-delay performance also is superior. Over a 260-MHz control-signal bandwidth, it yields improved ACLR performance. In addition, the MAX204x family provides the reliability and ESD robustness that only a silicon-based (SiGe) process can deliver.

With their high switching speed, these devices are tailored for both feed-forward and hybrid digital predistortion-based designs. An on-chip RF gain amplifier provides 8 dB of gain, thereby eliminating the need for an expensive external amp. To simplify interfacing, the MAX204x family has both current- and voltage-mode inputs.

More specifically, the MAX2045/MAX2046/MAX2047 low-cost, fully integrated vector multipliers alter the magnitude and phase of a radio-frequency signal. Each device is optimized for the UMTS (MAX2045), DCS/PCS (MAX2046), or cellular/GSM (MAX2047) frequency bands. The MAX2045/MAX2046/MAX2047 provide vector adjustment through the differential I/Q amplifiers. Those amplifiers can interface with voltage and/or current digital-to-analog converters (DACs). The voltage inputs are designed to interface to a voltage-mode DAC, while the current inputs are designed to interface to a current-mode DAC. An internal 2.5-V reference voltage is provided for applications using single-ended voltage DACs. The MAX2045/MAX2046/MAX2047 operate from a 4.75- to 5.25-V single supply.

The MAX2045/MAX2046/MAX2047 devices and corresponding evaluation kits are now available. Each device comes packaged in a compact 5-x-5-mm, 32-pin QFN package. Prices start at $8.93 (1000-up, FOB USA).

For additional information on these products, go to www.maximic.com or call (800) 998-8800.

San Jose, California
Xilinx, Inc. has unveiled a new family of programmable chips known as Spartan-3. It is expected to propel programmable-logic devices further into the high-volume, low-cost applications that are traditionally served by custom chips with fixed architectures.

Leveraging both 90-nm and 300-mm advanced manufacturing technologies, the Spartan-3 family achieves unprecedented density and price for field-programmable gate arrays (FPGAs). By setting a new FPGA price-density standard, Xilinx will be able to target a $23 billion total available market (TAM). At the same time, it will be able to address new higher-volume applications in the application-specific integrated-circuit (ASIC) market.

Xilinx invested in 90-nm and 300-mm chip-making processes with dual fabrication partners IBM and UMC. Now, this investment has enabled it to achieve an 80% chip-size reduction compared to competitive products on 130-nm technology. With prices starting at under $3.50, Spartan-3 platform devices range from 50,000 to 5 million system gates.

Simply put, it is the world's lowest-cost FPGA family. Pricing is at just under $20 for a one-million-gate FPGA and just under $100 for a four-million-gate FPGA. That's a cost savings of up to 80% over competitive offerings. To date, Xilinx has shipped Spartan-3 devices to customers from both fabrication partners.

The new 90-nm Spartan-3 platform is built on the proven success of the Spartan Series products. Such products have been broadly adopted in high-volume, high-growth consumer applications. This is the most difficult high-volume market to penetrate. It also is the one that has been historically dominated by ASICs. Since its introduction in 1998, Xilinx has shipped more than 50 million Spartan Series devices. They have been designed into innovative products ranging from set-top boxes and plasma-display televisions to automotive telematics.

The new Spartan-3 family consists of eight devices at prices starting below $3.50. First customer shipments of the new Spartan XC3S50 (50,000 system gates for under $3.50) and XC3S1000 (1 million system gates for under $20) began last month. Additional family members will begin shipping this summer. The entire Spartan-3 family will be available in volume production in early 2004 from distributors worldwide. For more information, contact the company directly at www.xilinx.com/spartan.

Sunnyvale, California
National Semiconductor now offers two new CMOS dual-input, low-dropout (LDO) voltage regulators with what is claimed to be the industry's lowest dropout. These devices include the LP3881—which generates a regulated 1.5-V output from a 1.8-V input—and the LP3882. Optimized for low-voltage, high-current applications in PCs and set-top boxes, this family of LDOs enables high-efficiency linear conversion while consuming an ultra-low quiescent current of only 3 mA under all conditions. In contrast, the quiescent current of bipolar alternatives increases to over 100 mA as the regulator approaches dropout.

National's family of LDO voltage regulators uses a separate input to power the control circuitry. The power input may be fed independently from the high current supply. This facilitates conversion from input rails of less than 2.5 V. The CMOS dual-input architecture allows for an ultra-low input voltage and low output voltages down to 1.2 V. The dropout voltage for the LP3881 and LP3882 is typically 75 mV at 0.8 A and 110 at 1.5 A, respectively. Additionally, the LP3881 features an overtemperature of 160 mV, while the LP3882 boasts an overtemperature of 270 mV.

The LP388x family's unique circuit approach enables the delivery of custom voltages in 50-mV increments in the range of 1.25 to 1.8 V. The family has an output-voltage accuracy of 3% over line, load, and temperature variations. It also features on/off control and overtemperature and overcurrent protection.

National Semiconductor's LP388x family of high-current, low-voltage CMOS LDOs is shipping today in TO220-5 and TO263-5 lead packages. In 1000-unit quantities, the LP3881 is priced at $2.08 each. In similar quantities, the LP3882 is priced at $2.18 each. To find out more about either product, go to www.nsc.com.

Milpitas, California
Linear Technology now offers the LTC3403 step-down regulator. This high-efficiency, 1.5-MHz, synchronous buck regulator with an integrated bypass MOSFET can deliver up to 600 mA of continuous output current from a tiny 8-lead DFN package. Using a constant-frequency current-mode architecture, the LTC3403 operates from an input-voltage range of 2.5 to 5 V. It is therefore ideal for single-cell Li-Ion cellular applications. The output can be dynamically programmed from 0.3 to 3.5 V to optimize the efficiency of the latest-generation CDMA and W-CDMA power amplifiers. It also will increase battery life.

At output voltages above 3.6 V, an internal-bypass p-channel MOSFET transistor connects Vout directly to Vbattery with a dropout of less than 100 mV (at 600 mA). This minimizes power loss through the inductor. Its switching frequency of 1.5 MHz allows the utilization of tiny, low-cost capacitors and inductors that are less than 1 mm in height. The combination of tiny externals and a 3-x-3-mm DFN package make the LTC3403 optimal for space-constrained cellular phones.

With a dynamic-output adjustability feature, the LTC3403 can constantly optimize the RF power-amplifier (PA) supply requirements. These requirements continually change, depending on the proximity of the nearest base station and its mode of transfer (voice or data). The internal p-channel MOSFET bypass transistor enables the LTC3403 to connect the PA directly to the battery for high-power transmission modes that require voltages above 3.6 V. At the same time, they maintain maximum efficiency. During lower-power transmission, the LTC3403 regulates the PA's supply voltage to a lower level to improve efficiency. To optimize light-load efficiency, the LTC3403 step-down regulator utilizes an automatic burst-mode operation. This operation enables a quiescent current of only 20 µA (less than 1 µA in shutdown). A selectable forced-continuous mode also enables a fast Vout response to the controlling input. Additionally, this regulator is stable with ceramic capacitors. It can achieve a very-low-output voltage ripple. The LTC3403 is an ideal solution for cellular applications that require bypass capability, moderate output current, and high efficiency from a very small form factor.

The LTC3403 is now available from stock. Pricing starts at $2.10 for 1000-piece quantities. Contact the company for further details at www.linear.com.

Hide comments

Comments

  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.
Publish