Wireless Systems Design

On The Wireless Front

Milpitas, California
Linear Technology Corp. recently introduced LTC4054—a single-cell linear Li-Ion battery charger with both on-board charge termination circuitry and power transistor. This device is housed in a 5-lead, 1-mm high SOT-23 (ThinSOT) package. It can deliver up to an 800-mA charge current without requiring an external transistor. Alternative solutions with an integrated transistor are housed in a package twice the size of the LTC4054. Moreover, other linear charger controllers in a SOT-23 package depend on an external transistor to deliver the same amount of current as the LTC4054. In addition to an integrated transistor, the LTC4054 also requires no sense resistor, blocking diode, or charge-termination control circuit. This allows a complete design to fit in just an 18-mm2 board area with 1-mm height.

To eliminate the risk of overheating, the LTC4054 product incorporates thermal-feedback regulation. This is achieved by automatically controlling the charge current to limit the die temperature during high-power operation or high ambient temperature. The LTC4054 keeps the battery "fresh" after charge termination by monitoring the battery's voltage and automatically recharging it if the voltage drops below a set threshold. Because of its standalone operation, compact solution, and low 4.25-V input supply operation, the LTC4054 is an ideal solution for charging a Li-Ion battery from the USB port in handhelds. The same is true for Bluetooth headsets, portable MP3 players, battery-powered GPS devices, PDAs, and cell phones.

The LTC4054 is a linear charger for single-cell, 4.2-V Li-ion and Li-Polymer batteries. The IC charges the battery in constant-current/constant-voltage mode and terminates charging after detecting C/10. The termination event is indicated by a Charge Status pin, which can signal a microcontroller or drive an LED. The user sets the charge current with a resistor. The float voltage is preset at 4.2-V with ±0.5% accuracy. By measuring the voltage on the LTC4054's PROG pin, the user can monitor charge current for the purpose of gas gauging. The LTC4054 operates from a 4.25-to-6.5-V input source.

Now available, the LTC4054 is priced at $1.40 each in 1000-piece quantities.

For more information, call the company at (800) 4-LINEAR or go to its Web site at www.linear.com.

San Jose, California
ZiLOG, Inc. now brings a new family of high-performance microcontrollers to the market. Known as the eZ80Acclaim! 8-b family of MCUs, these devices deliver enhanced performance, embedded Ethernet media access controller (MAC), and Flash memory to a host of 8-b applications. Such applications range from consumer electronics and security systems to industrial control and embedded networking.

The eZ80 MCU family consists of three products: the F91, F92, and F93. Each offers a wide array of peripherals and 256 kB of Flash memory. Designed to enable easy, direct connections to Ethernet networks and the Internet, these new devices also include an on-chip eZ80 Ethernet MAC, embedded TCP/IP, a host of other standard protocols, and a complete hardware/software design kit.

All three eZ80Acclaim! devices offer backward compatibility with the Z80 family of MCUs. This allows existing Z80 designers to quickly get up to speed on the new architecture. At the same time, new users can take advantage of the product's quick time to market, low system cost, and integrated connectivity to rapidly build embedded solutions.

The F91 microcontroller includes a clock speed of up to 50 MHz, as well as the ability to address 16 MB of address space and perform 24-b integer arithmetic. When combined with on-chip peripherals, the new controller enables design engineers to create a new class of powerful 8-b applications.

Along with 256 kB of Flash program memory, the F91 adds an extra 256-B device-configuration Flash memory and 8 kB of on-chip high-speed SRAM with access speeds of less than 20 ns. The chip also includes four counter/generators, a watchdog timer with an internal RC clocking option, and a real-time clock with both an on-chip 32-kHz oscillator and a PLL with an on-chip oscillator. In contrast to the F91, the F92 and F93 products are designed for more cost-effective applications that only require 20-MHz performance and a subset of the features found on the F91.

To help designers quickly develop a wide variety of embedded systems, ZiLOG provides full development support for the eZ80Acclaim! family. This support includes a full-function ANSI C compiler with debugger, TCP/IP stack, OS, and evaluation hardware. An Ethernet development module is also included. A comprehensive development board with an eZ80Acclaim! MCU plug-in module allows designers to quickly test out their designs. The ZiLOG Developers Studio Integrated Development Environment (ZDS IDE) adds an assembler, linker, debugger, and simulator to the mix to simplify and accelerate software design.

The eZ80 Acclaim! family of products is now available. The F91 MCU comes in a 144-pin package, while the F92/F93 products come in a 100-pin package. Contact the company directly for pricing information or go to its Web site at www.ZiLOG.com.

Irvine, California
Toshiba's Storage Device Division (SDD), which is known for its pioneering work in small-form-factor hard-disk drives (HDDs), recently announced what it claims to be the industry's first 60-GB, 5400 RPM drive in a 9-mm form factor. This super-slim, 2.5-in. hard drive (MK6022GAX) provides this level of performance and capacity in a design that enables mobile manufacturers to upgrade their customers' usage experience with faster and thinner computing and entertainment devices.

Toshiba's 5400 RPM 60-GB hard drive allows users to access more data in less time. As a result, a significant improvement in system-level performance is achieved. With an areal density of 49.8 Gb per square inch, the 60-GB capacity is achieved using two platters and four heads in the 9.5-mm package. Because of this, Toshiba's hard-drive family is extremely well suited to accommodate the storage needs of multi-functional mobile PCs and non-PC applications. This might include such things as telecommunications, printers, copiers, and MP3 players.

Toshiba's 60-GB hard drive contains an ATA-5-compliant interface to support high transfer rates of 100 MBps. It can withstand operational shock of up to 200 G and non-operating shock of up to 800 G. Some of its specific characteristics include an average seek time of 12 ms, a TPI of 78.9 K, and a BPI of 632 K (max). Additional features include an energy consumption of 0.014 W/GB, a 16-MB buffer memory, and a low-power idle of 0.85 W.

The MK6022GAX hard drive is now available. For more technical details on the part or for specific pricing information, go to www.harddrives.toshiba.com or www.sdd.toshiba.com.

Essex, Vermont
Huber + Suhner has now come to market with a coaxial connector that is a type-N alternative. Its claim to fame is that it has a very low IMD (which generally comes from keeping nickel and other easily magnetized materials out of the connector). This translates into high dynamic range in base-station transmitters.

According to the company, this product line—the QN connectors—comprises the first practical alternative to Type N connectors in some time. The connectors are capable of operating from DC to 11 GHz with low IMD and high power-handling capabilities. While the QN connectors are optimized for use from DC to 6 GHz, they can easily provide low-loss performance through 11 GHz.

These connectors can be fitted on flexible and corrugated cables, as well as on semi-rigid cables. Each can handle power levels of up to 300 W CW at 2.5 GHz. Through careful selection of materials, the connectors achieve extremely low levels of IMD, typically better than -155 dBc. This makes them especially well suited for use in the transmit path of mobile-radio base stations. Because they incorporate a compressed O-ring gasket to achieve IP68 water protection, the connectors are also ideal for outdoor applications, including connections between a mobile-radio base station and antennas.

The quick connect/disconnect QN connectors feature a unique snap-lock design, which requires about one-tenth the connector/cable assembly time of threaded Type-N connectors. A QuickLock mechanism provides for an audible snap that can be heard when the connectors are locked into place. That same sound is made when the connectors are unlocked by pulling back on a nut release.

Mating times for the QN connectors are typically 2 to 7 sec. In contrast, demating times are typically 2 to 5 sec. A special spring-loaded contact element on the connectors ensures steady and uniform contact of the outer conductors. Roughly 30 N of force is required to couple or uncouple QN connectors.

Huber + Suhner's QN connectors support higher package densities than conventional Type-N connectors. In addition, they feature full 360° rotation of the plug. This reduces the stress on cable assemblies and eliminates the need for any retightening of the hex nuts after installation.

Now available, the QN connectors can be purchased as either cables or in a panel-mount version for use with enclosures and packaging. For specific pricing information, contact the company directly at www.hubersuhnerinc.com.

EiC Corp. recently announced a major breakthrough in power-added efficiency (PAE) for CDMA and W-CDMA mobile applications. On the heels of this announcement comes the introduction of three new 4-x-4-mm power-amplifier-module (PAM) devices. Dubbed the ECM06x series, these devices are now available for sampling.

The ECM060, ECM064, and ECM068 have each been specifically designed for W-CDMA, CDMA PCS, and Korean PCS applications, respectively. All devices boast exceptional efficiency. In fact, the company has attained a 2% to 5% improvement in PAE over conventional PAM solutions. This translates into less current draw and more battery life for the next generation of cell phones, PDAs, and other notebook or personal-communication devices.

The ECM060 device, for example, boasts a 43% PAE, while the ECM064 device registers a 40% PAE. The ECM068 device also flaunts a 40% PAE. Additionally, the ECM060, ECM064, and ECM068 products are characterized by a gain of 27 dB and a Po of 27 dBm, 28 dBm, and 28 dBm, respectively. The ECM060, ECM064, and ECM068 products also feature an Icc of 335 mA, 450 mA, and 450 mA, respectively. The ECM060 operates at a frequency of 1.95 GHz. In contrast, the ECM064 device has a 1.88-GHz frequency, while the ECM068 has a 1.78-GHz frequency.

The ECM06x series products maintain quiescent current as low as 50 mA from no RF power to maximum 28-dBm RF-power output. This is possible without employing Q-Control step biasing. The Q-Control feature was introduced in EiC's previous family of PAMs to ensure lower quiescent current and higher efficiency at lower power levels. The need for this stepped bias or switching action has been eliminated by a patent-pending circuit design employed by the company's engineers. This circuit concept effectively allowed the company to realize improved efficiency and lower current draw without the deployment of Q-Control stepping. The result is greater ease of design for the user's system.

The ECM060, ECM064, and ECM068 products each come in a 4-x-4-mm LCC package. Contact the company directly for samples and pricing. It can be found at www.eiccirp.com or by calling (510) 979-8953.

Pittsburgh, Pennsylvania
Ansoft Corp. is now shipping a commercial version of its Ansoft Designer product. This electronic-design-automation (EDA) software environment is targeted for use in the design of high-frequency microwave and RF circuits and systems. It brings together Ansoft's complete family of linear and nonlinear circuit simulators with the company's 3D planar electromagnetic solver. Its tight integration makes the design environment capable of solving, verifying, and optimizing even the most complex circuits rapidly and from within a single user interface.

Ansoft Designer combines time-domain, frequency-domain and system-level analysis tools in one package. This allows the user to accurately and efficiently investigate the relationship between physical-design aspects and electrical performance. All of this happens before actually fabricating circuit, subsystem, or system components.

A key component to this software release is the Ansoft Solver on Demand technology. This technology gives every user, from novice to veteran, access to the most appropriate solver for a given design problem. In particular, it provides for electromagnetic, circuit, and system co-simulation of next-generation RF circuits.

With Ansoft Designer, all tools are always available for use, regardless of the task being performed at a specific time. The subsequent result is greatly reduced design time and complexity. Additionally, there is a greater assurance for the user that a given circuit will operate as expected without further iterations.

The Ansoft Designer software environment can operate as a standalone tool. Or it can be incorporated into existing design flows based on third-party EDA software-design tools. Some of the vendor tools supported include those from Cadence, Synopsys, Mentor Graphics, and Zuken.

Ansoft Design, with its Solver on Demand Technology, is now available. Pricing starts at $31,900 (U.S. list price). The software environment is supported on Windows 2000 (SP2 or higher) and XP. Further information on this product can be obtained at www.ansoft.com/ansoftdesigner.

Santa Barbara, California
Superconductor Technologies, Inc. (STI) has new field-trial data to report. This data was collected via testing with a major wireless carrier. The results show a significant reduction (43%) in dropped and blocked calls (26%) for a network utilizing the company's SuperLink Rx cryogenic receiver front-end solution in an urban cluster. These results are not only significant from an overall network-performance standpoint. They also allude to the fact that wireless operators may reap a benefit in terms of cost. That's because the operators can now stretch the performance of their existing networks without having to make significant hardware and/or software investments—other than the SuperLink Rx 850 product. According to the company, even using conservative estimates on the cost savings from fewer dropped and blocked calls, the SuperLink Rx 850 products will pay for themselves in under six months.

The field trial tests were conducted on an already benchmarked urban network. The tests took place during the network's busy hours. During the trial, it was established that more than 5000 dropped calls and nearly 2500 blocked calls were avoided per week, thanks to the performance enhancement of the SuperLink Rx Solutions.

The SuperLink Rx solution is a state-of-the-art cryogenic receiver front end. It uses high-temperature superconducting technology to improve the connection between the wireless operator's cell site and its customer. The solution uses less power than an ordinary light bulb. It has demonstrated a mean time between failure (MTBF) of more than 500,000 hrs. To find out more about this product or the company's superconducting technology, go to its Web site at www.suptech.com.

Sunnyvale, California
Maxim Integrated Products just introduced what is considered to be the world's first 2.5-GHz LVECL/LVPECL 8:1 multiplexer. This product, the MAX9389, is a single, low-skew differential LVPECL/PECL/LVECL/ECL 8:1 multiplexer. It has been specifically designed for clock and data redundancy, as well as multiplexing circuits. It is ideal for applications that include such things as mass storage servers, DSLAMs, base stations, automatic test equipment (ATE), central-office switches, networking switches, and routers. It is also well suited for communications applications in which low jitter is critical for signal integrity (e.g., 1.15-ps RMS maximum added random jitter at 2.5 GHz). Additionally, the MAX9389's two identical outputs make it useful in redundant systems.

The MAX9389 multiplexer operates over a wide 2.375-to-5.5-V supply range in PECL (5.0-V) or LVPECL (3.0-V and 2.5-V) systems. In LVECL (−2.5-V and −3.0-V) and ECL (−5.0-V) systems, it operates over the −2.375 to −5.5-V supply range. Its differential outputs are specified at 300 mV at a 2.5-GHz minimum switching frequency over the extended temperature range of −40°C to +85°C.

The MAX9389 product is now available in volume production. It comes in a 32-pin TQFP or QFN package. Pricing starts at $9.00 (U.S. list price).

Maxim Integrated Products also is now offering the MAX9386, MAX9387, and MAX9388 multiplexer products. Each device boasts performance that is similar to that of the MAX9389 LVPECL/PECL/LVECL/ECL 8:1 multiplexer. For more technical details or additional information on any of these products, or to inquire about specific pricing, please contact the company directly at www.maxim-ic.com.

Norcross, Georgia
EMS Technologies now offers the Cobra Series line of variable electrical downtilt (VED) antennas. It is designed to assist wireless carriers in saving money while optimizing their networks. The series encompasses all the company's VED antennas and is available in both cellular and PCS models.

Key features of the antennas include an easily turnable knob that locks in place in the face of severe vibration tests, and consistent patterns through the range of downtilts. Additionally, these antennas have no PIM issues because the products do not allow metal-on-metal contacts.

For carriers with both 800 and 1900 frequency bands in their markets, EMS Technologies also has a dualband VED. This product includes the variable downtilt on the cellular antenna with a fixed downtilt on the PCS side. The product is available on a large variety of EMS model numbers and antenna options. Beginning in the second half of 2003, EMS Wireless—a division of EMS Technologies— will also offer a Remote VED (RVED) product that can be controlled from the ground. RVED will be ideal for PCS carriers facing costly tower installations. For more information go to www.ems-t.com.

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