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Communications
-- EDN, 12/9/1999
Plastic is the key to cost-saving RF GSM family. By putting all the RF power devices for the 900-MHz Global System for Mobile communications (GSM) market in plastic packages, Motorola brings potential cost savings of 40% to your design. The company's plastic LDMOS devices are surface-mountable, gold-free, and have thermal impedance of approximately 1.2°C/W. The first devices to use this plastic packaging are the $20 (10,000), 10W MRFIC5001 IC with 26-dB gain in a PFP-16 package and the MRF9045P 45W, 1-GHz discrete MOSFET in a PRFP-1 package. Motorola's reference design for these parts uses the IC to drive two of the transistors, producing 70W of power in the 925- to 960-MHz GSM band. Motorola Semiconductor Products Sector, Phoenix, AZ. www.motorola.com/sps/rf.2.5-Gbps chip set eases SONET connectivity. The VSC9111 transport-terminating transceiver, the VSC8140 16-to-1 transceiver, and the VSC7958 limiting postamplifier make it easier to design 2.5-Gbps links. The VSC9111 is an interface among four STS-12/ STM-4 data streams or 16 STS-3/STM-1 data streams and a single STS-48 data stream; it terminates SONET/ SDH section and line overhead. The 352-pin, $177 (1000) BGA device has a generic 8-bit processor interface for device configuration, status-and performance-data transfer, and test-mode operation. For serialization, deserialization, and clock generation in OC-48/STM-16 systems, the VSC-8140 transceiver operates from a 77.76- or 155.52-MHz clock, which it multiplies using its internal PLL. The 128-pin, $155 (1000) PQFP device has an onboard FIFO buffer to eliminate loop-timing constraints as you use its 16-bit parallel port. The Vitesse VSC7958 limiting postamplifier provides a fully differential I/O path and on-chip offset correction to minimize pulse-width distortion. Input noise for this 16-pin, $95 (1000) IC is 160 mV. Vitesse Semiconductor, 1-805-388-3700, www.vitesse.com.
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Direct-conversion GSM chip set gives superhet designs something to worry about. The ADS6523/6524 chip set for Global System for Mobile communications (GSM) not only implements a zero-IF architecture but also overcomes the impediments and weaknesses of previous attempts to perform this task. The result is a low-component-count, low-board-space design for a GSM cell phone with few external components and without performance compromise. The Othello chip set comprises the AD6523 IC in a 28-lead TSSOP and the AD6524 IC in a 20-lead TSSOP. The RF AD6523 includes full receive and transmit paths, a low-noise amplifier, and a low-dropout amplifier. The AD6524 is an ultra-fast-locking, fractional-N synthesizer plus crystal oscillator. Analog Devices Inc, 1-781-937-1428, www.analog.com.
OC-48 chip features on-chip FEC. The multirate OC-48 three-chip set from Applied Micro Circuits Corp (AMCC) integrates forward-error correction (FEC) for dense-wavelength-division-multiplexing applications. The S3062, a CMOS device, provides encoding, decoding, and performance-monitoring functions. The S3062 can optionally decode and encode data entering or leaving a chip with FEC information or differential coding. A processor interface, an FPGA interface, or signal pins on the I/O provides access to detected- and accumulated-error counts. AMCC fabricates the S3066, a clock- and data-recovery chip, and the S3067-an integrated multiplexer/demultiplexer-with FEC using silicon-germanium process technology. The S3066 provides FEC capability of 3 to 8 bytes per 255-byte block and includes an on-chip PLL comprising a phase detector, a loop filter, and a voltage oscillator. The S3067 multiplexer/demultiplexer offers a high-frequency PLL for clock synthesis, allowing the use of a slower external transmit-clock reference. All devices can operate at Gigabit Ethernet, synchronous-optical network/synchronous-digital-hierarchy, OC-48, OC-12, or OC-3 scrambled-NRZ frequencies, using 3.3V power supplies for a combined power consumption of 5.7W. The S3062 comes in a 352-bump SBGA and costs $245, the S3066 comes in a 48-bump TQFP/TEP and costs $72, and the S3067 comes in a 156-bump TBGA and costs $150 (1000). Applied Micro Circuits Corp, www.amcc.com.
Passive RFID tags push to 13 MHz, embed anticollision techniques. The MCRF355 and similar MCRF360 radio-frequency ID (RFID) tags from supplement-or even replace-conventional bar codes in applications such as inventory control, library-book tracking, and parcel shipping. The tags operate at 13.56 MHz with as much as 154 bits of user memory, which you can "contact-program" before using the tags in write-once, read-many applications. The tags use the backscattering principle, whereby the tag uses amplitude modulation to "load" the electromagnetic field that the scanner generates to convey information. The MCRF355 requires an external resonance capacitor, which can be part of your circuit layout; the passive MCRF360, which has no internal power source, has an on-chip capacitor. These ICs are available in wafer, wafer-on-frame, DIP, and SOIC packages; prices start at 30 cents (10,000). Microchip Technology Inc, 1-602-786-7200, www.microchip.com.
Embedded antenna supports both cellular/PCS and Bluetooth bands. The latest member of RangeStar International's Performa series of cellular/personal-communication-system (PCS) embedded antennas operates on the 2.4-GHz industrial, scientific, and medical (ISM) band. This feature lets you implement wireless phones that support Bluetooth with only one antenna system. The T-planar antenna, an efficient resonator, acts as the frequency-determining element of an asymmetrical dipole antenna. The ground traces provide the second half of the dipole. These ground traces reside near or at one end of the printed-wiring board of a wireless device in which a 50? line is available to feed the antenna system. The dual-band antenna features a gain of 0 to 1 dBi on the cellular/PCS band and 0 dBi on the ISM band. The antennas cost less than $3 each (OEM). RangeStar International, 1-888-647-7100, www.rangestar.com.
New communications processor does it all. The C-5 digital-communications processor (DCP) from C-Port targets a range of communication applications-from high-function Ethernet switches and multiservice access platforms to terabit routers and optical edge switches. The C-5 provides a platform for more functions including traffic classification, policy enforcement, virtual-private-network and MPLS (multiprotocol-label-switching) services, and quality-of-service scheduling, all at wire speeds. The C-5's channel processors handle incoming signals, supporting data rates from multiple DS-1s to an aggregate of 5 Gbps (OC-48). The C-5 also supports the collection of real-time flow statistics, as well as multiple simultaneous look-up algorithms for "universal" applications, such as interconnecting networks requiring different look-up algorithms. Volume prices for the C-5 DCP start at $400, and samples are available. C-Port Corp, www.cportcorp.com.
IC provides Internet-ready TCP/IP stack. The iChip S7600A Transmission Control Protocol/Internet Protocol (TCP/IP) stack allows you to easily and inexpensively add Web-browsing, e-mail, and networking utilities to consumer or commercial devices. The TCP/IP stack on the chip acts as an accelerator between an X86-type or 68000-family µP and the Internet or any network that uses the protocol. The device is suitable for use in personal digital assistants, cell phones, and even pagers. The iChip S7600A runs at a typical speed of 256 kHz and consumes less than 3 mW of operating power. It costs $8 (1000). Seiko Instruments USA, 1-800-934-9334, www.seiko-usa-ecd.com.
Module makes light work of extending gigabit fiber-optic link. With the GBE1250ELX optical transceiverfrom Cielo, you can extend a 10-km fiber-optic link to 100 km (typical) and 70 km (minimum), suitable for LANs, storage-area networks, and metropolitan-area networks (MANs). For MANs, it lets you bypass the telephone system as a local-exchange carrier for your backbone-to-backbone switch path, thus yielding significant cost savings. The module supports 1.0625-Gbps ANSI X3T11.2 Fibre Channel and 1.250-Gbps IEEE 802.3z Gigabit Ethernet links and consumes 1.1W. Each module costs $1300 (100). Cielo Communications Inc, 1-303-460-0700, www.cieloinc.com.
