Wireless Systems Design

On The Wireless Front

Milpitas, California
Linear Technology Corp. recently announced the LT3471. This dual-channel (boost/inverter), 1.3-A, 1.2-MHz DC/DC converter is packaged in a 3-x-3-mm DFN. It can be configured as a dual boost, boost/inverter, or dual inverter, as the output-voltage-error amplifiers can sense to ground. They therefore provide boost or inverting control capability. The LT3471 input voltage range of 2.4 to 16 V makes the LT3471 ideal for Li-Ion, multiple-cell Alkaline/NiMH batteries as well as 12-V power. The device's low VCESAT bipolar switches enable it to deliver 42-V high-current outputs from a tiny, 9-mm2 package. The LT3471 switches at 1.2 MHz, allowing the use of tiny, low-cost, low-profile inductors and capacitors. High-in-rush current at startup is eliminated using a programmable soft-start function, whereby an external RC sets the current ramp rate. A constant frequency-current-mode PWM architecture results in low, predictable output noise that is easy to filter.

The LT3471 switches are rated at 42 V, making the devices ideal for boost converters up to 40 V as well as SEPIC and flyback designs. Each channel can generate 5 V at up to 630 mA from a 3.3-V supply or 5 V at 360 mA from four alkaline cells in a SEPIC design. The LT3471 is available in a low-profile (0.75-mm), 10-lead, 3-x-3-mm DFN package. It claims to provide the smallest solution for high-current, dual boost/inverter applications.

The LT3471EDD is available from stock. Pricing starts at $2.80 each for 1000-piece quantities. To learn more, please visit the company web site at www.linear.com.

San Jose, California
With its latest version of Quartus II software, Altera is introducing the PowerPlay technology suite. This tool is comprised of advanced tools for programmable-logic power analysis and optimization. The analysis features that are included in the PowerPlay suite offer detailed estimates of static and dynamic power. They also assist a designer during the entire design cycle-from design conception through implementation.

Designers can use the PowerPlay early power estimator spreadsheet at the outset of a project to estimate static and dynamic power consumption. During the implementation phase, designers can refine power estimations by using the new PowerPlay power-analyzer tool. This tool improves estimation accuracy by combining an advanced "vectorless-power-analysis" algorithm with place-and-route results. If optional functional simulation vectors or gate-level simulation vector input are used, designers can expect even more accurate estimations.

The PowerPlay analyzer tool also offers detailed insight into a design's power-consumption profile, allowing a designer to scrutinize total power by design resource or hierarchy. Armed with this data, designers can quickly target optimization efforts to meet power budgets. Throughout 2005, additional features will be added to the PowerPlay suite. Such features include automated optimization tools. The PowerPlay power-optimization tools will provide designers with an efficient, automated way to optimize power consumption in field-programmable-gate-array (FPGA), complex programmable-logic device (CPLD), and structured application-specific-integrated-circuit (ASIC) designs. Version 4.2 also includes over 100 new features and enhancements to support advanced FPGA, CPLD, and structured-ASIC designs. For more information, please visit www.altera.com.

Santa Clara, California
National Semiconductor Corp. expanded its high-performance precision-amplifier portfolio with the addition of three high-common-mode difference amplifiers. Designed for broad-based industrial, commercial, and automotive applications, these new amplifiers meet the requirements for accurate current-sensing measurements in products like battery charging and discharging for notebook computers and cell phones. They also satisfy the demands of fuel-injection control.

The LMP8270 and LMP8272 high-common-mode amplifiers and LMP8271 high-common-mode bidirectional amplifier join National's linear-monolithic-precision (LMP) product family. That family targets the precision market. The bidirectional LMP8271 measures charge and discharge currents at high-common-mode voltages, which are typically found in precision applications. It uses an external reference voltage to set the voltage defining a zero-current condition. An LMP8271 output voltage greater than the external reference voltage indicates a charging current condition, while an output voltage below the external reference voltage identifies a discharging current condition. Accurate bidirectional load-current measurements are achieved when monitoring the output with respect to the reference voltage.

The LMP8270 and LMP8272 are unidirectional, fixed-gain differential-amplifier products. They will detect, amplify, and filter small differential signals in the presence of high-common-mode voltages. For the LMP8270 and LMP8271, the gain is fixed at 20. For the LMP8272, the gain is fixed at 14. These parts have a -2-to-27-V input common-mode voltage range and a supply-voltage range of 4.5 to 5.5 V. They function over an extended common-mode input voltage (-5 to +36 V) . For more information on National's amplifier products, visit http://amplifiers.national.com.

Sunnyvale, California
Maxim Integrated Products added the MAX9850, a stereo-audio digital-to-analog converter (DAC), to its line of high-performance, audio integrated circuits. The MAX9850 features built-in DirectDrive headphone amplifiers. The DAC operates from any 1.8-to-3.6-V single supply. Optimized for low-voltage operation, it delivers 30 mW of output power from a 1.8-V supply. The device is designed to meet the board-space and performance requirements of portable devices like cell phones, MP3 players, and portable DVD players.

This new audio digital-to-analog converter uses the company's patented DirectDrive architecture, which produces a ground-referenced output from a single supply. It thus eliminates the two bulky DC-blocking capacitors that are commonly used between the amplifier and the headphone. The removal of the two large caps makes more efficient use of board space-up to eight times less than alternative solutions. Because the audio signal is driven directly to the headphone, it enhances the low-frequency response of the system. The result is full-range audio reproduction, which is especially important for music and video playback. The DirectDrive architecture does not require the headphone jack to be biased to a DC voltage. It also allows a conventional grounded chassis design, thereby greatly simplifying system design and improving long-term reliability.

In addition, the output-clocking circuitry of the MAX9850 derives all common audio rates from an arbitrary master clock up to 40 MHz. The flexible architecture uses any available system clock. It eliminates the need for an external phase-locked loop (PLL) and multiple crystal oscillators. The device supports a wide range of sample rates from 8 to 48 KHz in both master and slave modes, making the MAX9850 easy to use and versatile.

To learn more about the MAX9850, go to the company's web site at www.maxim-ic.com.

San Jose, California
Xilinx, Inc. announced the immediate availability and shipment of its Virtex-4 LX100 device, which it claims is the world's highest-capacity FPGA. Featuring over 110,000 logic cells and a host of embedded functionality, the LX100 integrates larger designs than any other FPGA available. In addition to its industry-leading capacity and feature set, the Virtex-4 family vows to deliver the highest performance and lowest power consumption of any high-density FPGA.

With the introduction of the LX100, design engineers now have a flexible, high-performance, low-power and cost-effective alternative to ASICs and ASSPs for high-complexity designs. Each Virtex-4 LX100 device includes a triple-oxide, 90-nm CMOS process. This process works to reduce power consumption by a factor of six compared to competing 90-nm FPGAs. The devices also flaunt an ASMBL architecture, which is optimized for high-performance logic applications. In addition, 96 500-MHz XtremeDSP Slices deliver aggregate DSP performance of 48 GigaMACs per second at power-efficiency levels of 23 µW/MHz.

The LX100 also houses 4.3 Mb of 500-MHz SmartRAM (configurable synchronous dual-port static RAM). The SmartRAM features integrated FIFO control logic to build fast FIFOs without consuming logic cell resources. The device's 960 I/Os feature 1-Gbps performance and ChipSync source synchronous technology with integrated bit- and word-alignment circuitry. Plus, SERDES is available on every I/O.

The LX100 features 500-MHz DCM Digital Clock Managers. It therefore offers sub-30-ps timing resolution and advanced clock synthesis and timing capabilities. For high-precision control of the skew and duty-cycle, it also boasts 500 MHz high-performance on-chip differential clock networks. To learn more about Xilinx's FPGAs, visit www.xilinx.com.

Seoul, Korea
Samsung Electronics Co., Ltd. announced the successful development of a 1-Gb OneNAND Flash-memory device. The device uses Samsung's advanced 90-nm process technology. By introducing this high-density OneNAND Flash-memory device, Samsung is expanding its diverse portfolio of Flash technology to fully support the advanced multimedia features associated with next-generation handsets and other mobile applications.

Samsung's OneNAND device provides a new Unified Storage concept. It combines the high-speed data read function of NOR Flash and the advanced data storage of NAND Flash. The single chip is based on NAND architecture integrating the buffer memory and logic interface. It features a 66-MHz synchronous interface and cache read function, which enable an enhanced read performance of 108 MBps. The 1-Gb OneNAND Flash boasts a fourfold read-speed increase over conventional NAND Flash performance. Its faster read speeds resolve the delay time in copying the boot code from the NAND Flash to the DRAM and executing applications on demand.

Today, a continuous multi-shot capability is limited to the DRAM buffer size. The 1-Gb OneNAND delivers 10 MBps of write speed. It therefore enables direct write into the total Flash-memory space without the need for DRAM buffering. This aspect provides continuous, multi-shot capturing of 5-Megapixel images and real-time recording of VGA resolution video. The OneNAND device also supports enhanced security features. An OTP block has been integrated into its design to prevent forgery. In addition, a lock function for the memory block unit is available to protect the operating system from viruses.

The OneNAND Flash solution is available separately or can be mounted together with a mobile SDRAM in an MCP to effectively execute the key operations on feature-intensive next-generation mobile phones. By placing two 1-Gb OneNAND Flash and one mobile SDRAM in a three-chip MCP, designers can satisfy the high-performance, multimedia memory requirements of 3G mobile handsets. For more information, please visit www.samsung.com.

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