- Buyers Guide
These RFICs provide all the major system blocks for digital, cellular, PCS and digital cordless telephone applications. Eight silicon-based versions are available that are divided into four families. The TRF1xxx series receivers feature conversion from RF to IF and a nominal supply voltage of 3.75 V; the TRF2xxx series synthesizers feature a nominal supply voltage of up to 3.6 V; the TRF7xxx series silicon MOSFET power stage features a nominal supply voltage of 3.6 or 4.8 V; and the TRF8xxx series amplifiers with power control feature a nominal supply voltage of 4.8 V.
Texas Instruments Inc., Wireless Communications Business Unit,
Dallas, TX (800) 477-8924, ext. 4500.
These high frequency SiGe chips consume less power than established silicon or GaAs technologies and achieve operating speeds that exceed the physical limits of pure silicon. The main application for these chips is modem communications equipment such as mobile and cordless telephones. In addition, the equipment feature good voice quality and long operating times. The weight of the chips is low because a smaller battery can be used due to their low power consumption.
TEMIC Telefunken Microelectronic GmbH,
Heilbronn, Germany (+71 31) 67-29-45.
400 MHz IF Quadrature Modulator/Demodulator
The model HFA 3726 400 MHz IF quadrature modulator/demodulator is a low cost baseband converter designed for use in IEEE 802.11 wireless local area network (WLAN) applications requiring data rates up to 2 Mbps. The device is designed for the company’s PRISM™ chipset and effectively converts baseband signals for all WLAN applications from personal communications to wireless local loop. The modulator/demodulator contains fewer components than other discrete designs and its low profile housing allows WLAN products to be compact. The low voltage design also delivers good battery life, which is important to portable PC users. The unit operates from 2.7 to 5.5 V with power-down control. In addition, the device includes a two-stage limiting IF strip, a quadrature modulator and a lowpass filter with a single cutoff frequency of 7.7 MHz.
Melbourne, FL (800) 442-7747.
Four new analog/digital ICs for fiber-optic communications networks are now available, including the 8:1 multiplexer, 1:8 demultiplexer, exclusive OR/NOR circuit and decision circuit, all designed to support optical carrier (OC-192) rates at 10 Gbps. The multiplexer and demultiplexer are used to transfer data to and from lower frequencies by synchronously merging/separating eight 1.25 Gbps data streams. The OR/NOR circuit is designed to extract a clock signal from a 10 Gbps high speed communication serial data stream. The decision circuit is a mixed-signal device designed to extract data from high speed serial bit data streams. Prices: less than $1000 in production quantities.
Oki Semiconductor, Sunnyvale, CA (408) 720-1900.
GPS Receiver Firmware
This firmware (version 1.50) supports the company’s two-chip Zodiac™ Global Positioning Satellite (GPS) receiver chipset and its Jupiter™ GPS receiver board. These developments are designed to improve overall GPS performance and to navigate more precisely through downtown urban canyon environments. In addition, the power management option reduces power consumption by approximately 50 percent. Prices: $55 (10,000) for the Zodiac chipset with version 1.50 firmware and $150 (100) for the Jupiter board with firmware enhancements.
Rockwell Semiconductor Systems Inc.,
Newport Beach, CA (800) 854-8099 or (714) 221-6996.
Software-programmable Modem Front End
The Alis series analog line interface solution is a software-programmable front end designed for use in analog modems that allows a single hardware solution to be created for all national telephone standards. The unit is a highly integrated silicon solution that combines a fully programmable DAA and a digital signal processing (DSP)-based codec, and combines the functions of a transformer, hybrid and ring detect into a clean and simple two-chip implementation. The unit is a front-end solution for a wide variety of facsimile or modem applications up to 56 kbps, including international, PCMCIA and HSP-based modems, and modem-on-motherboard designs.
Munich, Germany +49 89 636-284 80.
The models SX071, SX072 and SX073 single-chip, modulator/oscillator ICs can be used to produce either a modulated or unmodulated 70 MHz carrier frequency,. Each device provides a different output option. The eight-pin SOJ (small outline j-leaded) package minimizes the required board real estate, making it suitable for PCMCIA applications. The ICs offer a low cost solution for modulating digital data streams of 10 Mbps to a 70 MHz IF data stream. The units are available for 5 and 3.3 V operations, simplifying interface requirements and reducing power consumption.
American Microsystems Inc. (AMI),
Pocatello, ID (208) 233-4690.
Switched Capacitor Voltage Converters
These 50 mA switched capacitor voltage converters are housed in SOT23-6 TinyPak packages. The model LM2664 unit inverts a positive voltage (+1.8 to +5.5 V) to the corresponding negative voltage (–1.8 to –5.5 V). The model LM2665 serves as a voltage doubler for supply voltages from 2.5 to 5.5 V. Due to their small size and high efficiency, both ICs are suitable for use in a variety of handheld battery-operated equipment. The units convert a range of supply voltages at a typical efficiency of greater than 90 percent. In addition, the ICs offer a low current shutdown mode with typical shutdown current of less than 1 mA. Price: 85¢ each (1000) for both models.
National Semiconductor Corp.,
Santa Clara, CA (408) 721-5000.