Tuesday, July 29, 2008

Link supplies 1119 solid-state high-power amplifier

The 1119 high-power amplifier is designed for mobile jamming applications.

Link Microtek, a specialist supplier of RF and microwave components and subsystems, has announced a solid-state high-power amplifier module designed for use in military mobile jamming systems to counter the threat of IEDs.

Manufactured by Empower RF Systems, the 1119 module covers the frequency range 500MHz to 2.5GHz and features a rugged construction that ensures excellent long-term reliability.

The module utilises high-power advanced GaN transistors to achieve an output of 50W with high efficiency, low distortion and wide dynamic range. It has a maximum noise figure of 10dB and a minimum IP3 of +48dBm.

Operating from a 28VDC supply, the 1119 includes built-in control and monitoring circuits to protect it against input overdrive, any load VSWR and thermal overload.

This compact module measures 188 x 91 x 27mm, weighs 454g and has an operating temperature range of -40º to +80ºC.

More information: www.linkmicrotek.com

Read more ...

Keithley guide to wireless and RF testing

This CD contains useful and informative RF testing resources, including application notes, articles, white papers, and product demonstrations, to help engineers reduce their cost of test by simplifying and solving the most challenging RF measurement applications. The CD is available free of charge at www.keithley.info/rfhandbookcdAdvanced Measurement Techniques for OFDM- and MIMO-based Radio Systems gives test engineers a broad range of information on the fast changing wireless communication and RF testing field for a wide array of applications, including spectrum analyzer power averaging, as well as the most challenging testing of the most complex signals, such as OFDM, MIMO, and WiMAX. In-depth application notes cover topics such as battery testing for mobile phones, RF semiconductor characterization, and RF and microwave signal switching in test setups. The CD also includes an RF glossary and useful tables, such as wireless communication protocol specifications, dbM-Watts-Volts conversion tables, and VSWR loss conversion tables.

Keithley Instruments, a supplier of products for emerging measurement needs, announces the Advanced Measurement Techniques for OFDM- and MIMO-based Radio Systems: Demystifying WLAN and WiMAX Testing, a new guide to wireless and RF testing.

More Information: To request a free copy of the CD Advanced Measurement Techniques for OFDM- and MIMO-based Radio Systems or for information on any of Keithley's RF test solutions, visit www.keithley.info/rfhandbookcd or contact the company at: www.keithley.com.

Read more ...

Monday, July 21, 2008

Paralleling power supply outputs for redundancy

The highest reliability attainable in a single power supply is not nearly as good as that of a redundant power system, in which the outputs of two (or more) power supplies are connected so that - even if one were to fail - the other(s) would continue to provide uninterrupted power to the load But implementing redundancy is not as straightforward as it may appear to be

To have a redundant power system that will function as intended requires careful consideration not only of the power supplies to be used and the electrical configuration, but also of the physical arrangement.

As every power supply will fail at some point, it's necessary to allow for quickly and easily replacing a supply that's failed or is in need of refurbishment.

For example, if the supplies are within an assembly mounted in an equipment rack, equip the assembly with slides so that it can be extended out of the rack for access - and don't forget to include handles on the front panel to pull it out.

Alternatively, some power supply manufacturers make supplies that can be plugged into the front panel of an enclosure or rack adapter, permitting a supply to be, quite literally, changed in a matter of seconds.

Another approach is to have the system's controls and indicators located on a main control panel, but to mount the power supplies in a more accessible location a few feet away.

And the supplies should be mounted in such a way that they can be easily and quickly removed and replaced - for example, by using thumbscrews.

Similarly, it must be possible to do the actual connecting and disconnecting of the power supplies quickly and easily.

If the supplies have screw terminals or lugs rather than connectors, then use insulated connectors that can be easily pulled apart in the wiring cable to each supply.

An isolation diode must be used in series with the output of each power supply, for two reasons - to avoid the possibility of the combined output being shorted if the output of one supply should short, and to prevent current from one supply flowing back into the other and reverse biasing it (which could cause it to malfunction and possibly damage it).

Obviously, the use of diodes introduces a voltage drop in the output voltage from the supply as seen by the load.

This is especially significant at low voltages; for example, a 5V output might drop to only 4V.

Using Schottky diodes can minimise the drop, but doesn't eliminate the need to allow for it.

Keep in mind that the supply must be capable of providing a voltage equal to the sum of the voltage required across the load, the diode drop and the drops (round trip.) in the wiring.

Particularly at low voltages, the lower drop of a larger gauge wire can be a big help.

A typical power supply can compensate up to a volt or so of drops in the wiring, but may not be capable of compensating both the wiring and the diode drops of a redundant system.

And if you're using remote sensing to regulate the voltage across the load, you might not be able to solve this problem by simply stepping up to a supply with a higher nominal output voltage (for example, going from a 5V supply to a 6V supply), because then the sense lines of that supply would try to maintain 6V across the load rather than 5V.

Therefore, be sure to use a supply that is capable of putting out a voltage high enough to compensate both the diode and wiring drops under worst-case conditions (usually, at low line voltage and with maximum rated load current being drawn), and also has the desired load voltage within its adjustment range.

A supply's maximum output voltage is usually considered to be the high end of its adjustment range; for example, a supply with an output specified as 24+/-1V could be relied on to provide a maximum of 25V, so if the load requires 24V and if the combined drops will be no more than 1V, you're in good shape.

Sometimes an easy solution to this potential problem is to use a wide range power supply; in the above example, a 0-30V supply adjusted to 24V would be capable of compensating "round-trip" drops up to 6V.

If two sources of AC power are available, providing separate AC wiring for each power supply permits using a different source of input power for each supply, resulting in the additional advantage of input power redundancy.

Even using two different branches of the same building power source will offer improved input redundancy.

A battery-backup UPS may also be used in series with one of the inputs, further improving overall reliability by permitting continued normal operation of the load even if both of the AC sources should fail simultaneously.

Although meters and/or indicator lights are helpful for monitoring, they don't command attention and may not be checked regularly.

However, an audible alarm can't be easily ignored.

Include an undervoltage alarm circuit on the output of each supply to detect if its output is lower than normal (or a relay can be used if you simply wish to know if an output is there or not), and use it to control an audible alarm, either built into the assembly containing the power supplies or remotely located where it will be heard.

The contact wiring for two or more relays can be cascaded so that only one audible alarm is required.

Checking the meters or indicator lights will then disclose which of the power supplies is low.

Power supply outputs don't always go low when they fail; with linearly regulated supplies, the series pass transistors can short and the voltage can instead go high - by 50% or more in some cases - and quickly fry the load.

Therefore, it's vitally important that power supplies used in redundant applications be equipped with overvoltage protection to assure that the output voltage can't go much higher than the nominal under any circumstances Don't use output fuses.

Virtually all power supplies today have output current limiting circuits that will drop the output faster than the time required for a fuse to blow, so including a fuse won't accomplish anything.

And with most supplies the current limiting automatically resets after a surge, while a blown fuse is counterproductive to the intent of a redundant power system - always having the output present.

Space the power supplies away from sources of heat.

If convection air flow is restricted, use a fan.

Overheating dries out capacitors, which is probably the single greatest cause of power supply failure.

And speaking of capacitor dryout, schedule testing of both supplies at least annually to be certain that each is capable of functioning properly.

If the capacitors are drying out (reducing the output current capability of the supplies) and the supplies are sharing the load, it's possible that working together they can support the load, but if one should fail the other won't be able to support it by itself.

Or, if one supply is set slightly higher than the other, the first will provide all of the current because the isolation diode of the other won't be forward biased; the voltmeter of the other may show that it's maintaining its output voltage, but that doesn't necessarily mean that it can support the entire load.

Slightly increase the output voltage of each power supply occasionally so that it will assume the entire load and verify that it can support the load by itself.

In summary, configuring a redundant power system isn't as simple as connecting two power supplies in parallel.

It requires careful consideration not only of how the power supply outputs may be affected by the manner in which they are connected, but also of factors that may affect both short and long term performance, and a physical arrangement that permits safe and fast maintenance while the system remains on line.

Read more ...

AVX tantalum capacitor for TPM low ESR multianode series

AVX has added a high capacitance to its low ESR tantalum capacitor product range for TPM series (low ESR multianode).

Key parameters of the new capacitor are a very low ESR of 18mOhm and a high capacitance of 2.200uF at 2,5V. 

The capacitor is available in E case packages (EIA Code 7343). It is ready to be used with high-performance processors which usually require a capacitance of 5.000uF and more for an operating voltage of approx. 1V. In the past 5x 1.000uF Low ESR Polymer capacitors have been used to achieve these target specifications.

By means of this new capacitance the capacitor count can be reduced to three, thereby cutting space and reducing costs.

The TPM low ESR multianode series is available as samples and series quantities from Rutronik, which is a broadline distributor for semiconductors, passive and electromechanical components in addition to wireless products, displays as well as embedded boards.

All product information stated in the current press release is based on the franchise situation in Germany and may vary by country.

More information: www.Rutronik.com

Read more ...

Power Integrations TOP260LN, TOP261LN and TOP262LN family of offline switcher ICs

The small package combined with the best-in-class efficiency and high operating frequency of TOPSwitch-HX enables slim, compact, and lightweight power supplies from 20 to 100 watts.

Applications include adapters for notebook computers, as well as power supplies for LCD monitors and flat-panel TVs, in which slim form factor and high efficiency have become critical design criteria.

The "L" shaped lead-bend allows the company's innovative eSIP package to lie flat against the printed circuit board with the heatsink pad facing upwards. The device stands 2 millimetres above the board giving space for a heatsink and enabling slender power supply designs.

The elegance of adapter designs enabled by the package is demonstrated by a new reference design (DER-196) for a 65 W notebook adapter only slightly larger than a standard deck of playing cards.  The design, which complies with the upcoming Energy Star 2.0 specifications for external power supplies, uses a TOP261 chip in the new eSIP-L package.

The efficient IC combines a 700 V switching power MOSFET with controller and supervisory functions into a single monolithic IC, reducing the need for bulky heatsinks required in designs using traditional TO-220 packaged MOSFETs and discrete controllers, and eliminating the need to encase the electronics with thermally-conductive potting compound.

The package's 90º pin deflection enables the PCB, chip and heatsink to lie parallel to each other, while the high switching frequency of TOPSwitch-HX eliminates the need for an expensive planar type transformer. This, together with Power Integrations' proprietary transformer design, greatly reduces both the cost and size of the notebook adapter.

Andrew Smith, product manager at Power Integrations, said: "TOPSwitch-HX has the best overall efficiency and lowest heat dissipation of any integrated flyback solution, which minimizes the surface area and heatsink hardware required to radiate the heat away from the electronics. The eSIP-L package delivers the same thermal performance as the older TO-220 package but with a much lower profile.  Until now, slim power adapters have tended to be sold after-market and use exotic technologies and even potting compound to achieve acceptable thermal performance – they're expensive. The combination of TOPSwitch-HX with the new low-profile lead-bend package makes it possible to build slimline adapters - just 15mm thick - using standard wire-wound transformers and simple manufacturing techniques at a cost similar to a standard laptop adapter brick."

TOP260LN, TOP261LN and TOP262LN devices suitable for slim adapters from 20 W to 100 W power levels are available in the eSIP-L package style from $1.00/ea in 10K unit quantities.

Power Integrations' Green Room website contains information on the issue of energy waste from inefficient power supplies, as well as tips on designing products that minimize the amount of energy wasted by household and office electronics. The Green Room also provides a comprehensive guide to energy-efficiency standards around the world, as well as a host of reference designs and software to assist in the design of energy-efficient power supplies.
More information: www.powerint.com

Read more ...

Tough Laser Module

Photonic Products industrial laser modules are constructed to withstand harsh conditions and satisfy rigorous application demands. The modules are encapsulated in a hard-coat anodised case with a scratch-resistant sapphire window to protect the lens and offer rugged, durable performance at an extremely economical price. When the laser needs to be changed, the connectors (either 2.5mm DC jack or industrial screw-on) facilitate easy installation. The modules' compact size allows for easy and efficient integration into existing production systems.

Source : Click here
Read more ...

International Rectifier IRS260xD family of single-phase high voltage ICs

International Rectifier has released the IRS260xD family of single-phase high voltage ICs for motor drive applications including air conditioners, fans, pumps, micro, mini and general purpose inverter drives.

These power Mosfet and IGBT drivers offer optional dependent or independent high- and low-side referenced output channels with a gate drive supply range from 10V to 20V.

The output drivers feature a high-pulse current buffer stage designed for minimum driver cross-conduction while the floating channel can be used to drive N-channel power Mosfets or IGBTs in the high-side configuration operating up to 600V.

The devices provide matched propagation delay for both channels and an advanced input filter to improve noise immunity in addition to negative voltage spike immunity to protect the system against catastrophic events during high-current switching and short circuit conditions.

The IRS2607D high- and low-side driver features outputs in phase with inputs and is suitable for both trapezoidal and sinusoidal motor control.

The IRS2608D and IRS2609D half-bridge drivers feature internal 540ns dead-time. 

The IRS260xD features under-voltage lock-out protection, integrated deadtime protection, shoot-through protection, a shutdown input and is compatible with 3.3V input logic.

See http://www.irf.com

Read more ...

picoChip surfing Wimax, Femtocell wave

picoChip, the Bath-based wireless start-up, is seeing a booming market for Wimax chips and an emerging femtocell chip market

picoChip, the Bath-based wireless start-up, is seeing a booming market for Wimax chips and an emerging femtocell chip market which should match Wimax for size next year.

"picoChip is the largest supplier of silicon to the Wimax infrastructure industry and the only supplier of silicon to the femtocell market", picoChip founder and COO, Peter Claydon, told Silicon South-West's recent Wireless 2.0 conference in Bristol.

"The Sprint/Xohm/Clearwire Wimax service in the US starts commercial launch in September which means we are selling more chips every month. It's quite a large amount", said Claydon, "and we sell a lot in Japan. We've been amazingly successful in the Japanese market. picoChip has 100 per cent market share in Japan because it sells to Samsung and Fujitsu. We have a good distributor there."

With Intel, Samsung, Motorola and Nokia putting Wimax chips into portable products like phones and laptops, and with the Japanese having recently completed a 2.5GHz spectrum auction for a next generation PHS system based on Wimax, the Wimax chip market is set to grow exponentially.

Asked if he's worried about Intel and Fujitsu getting into the Wimax chip business, Claydon replied: "Intel are going to put Wimax chips into laptops. We are focused exclusively on the wireless infrastructure side. Intel don't see the value in the infrastructure side, the value in laptops is a lot higher. Fujitsu sells to the terminal side not the base-station side."

Read more ...

Wednesday, July 16, 2008

Renesas Technology R8C/Tiny Series 16-Bit MCUs grow by 36 models

These include the 80-pin R8C/38E group, 64-pin R8C/36E group, and the 48-pin R8C/34E group. Together they strengthen the R8C/Tiny Series line-up for in-vehicle automotive equipment applications.

Available during October 2008, the MCUs feature on-chip flash memory, a built-in precision clock oscillator, and enhanced functionality, as well as packages with extra I/O pins. Moreover, within each of these three groups, there are MCUs with or without a CAN1 (controller area network) interface, with various amounts of flash ROM and RAM (32KB/2.5KB, 48KB/4KB, and 64KB/6KB), and with or without on-chip 4KB of data flash2 (data storage flash memory). Versions of the chips are available in two operating temperature ranges: standard (-40 to +85ºC) and extended (-40 to +125ºC).

The greatly expanded R8C/Tiny product line, now encompassing functionally compatible models with 20-, 32-, 48-, 64-, and 80-pin packages, makes it easier for automotive engineers to find the best, most economical MCU solution for any particular set of application requirements.

Also, the broader span of choices allows them to readily accommodate the specification modifications that often arise during the development and fine-tuning of MCU-based body-control systems. They can add functions or increase memory capacity, for example, just by switching to another R8C/Tiny device. This flexibility saves cost and time by eliminating the need for major design changes.

The MCUs in the R8C/38E/36E/34E groups provide improvements in various on-chip peripheral functions. For example, the high-speed on-chip oscillator has improved oscillation precision: ±1%, the industry's highest ranking. This feature eliminates the external resonator that would otherwise be needed to implement the clock circuit, enabling system cost reductions while also helping to boost reliability.

The data flash built into some of the new R8C/Tiny models eliminates the need for external EEPROM (electrically erasable and programmable read only memory) for data storage. It now has a background-operation (BGO) function that allows the CPU to execute instructions during data flash reading or writing. This boosts the MCU's processing efficiency and also allows system engineers to write programs without concern for data flash read/write times, simplifying program development. The size of the data flash capacity has been doubled to a total of 4KB (1KB × 4 blocks) compared with previous products, so more data can be stored.

The devices that expand the R8C/Tiny line-up include a data transfer controller (DTC) that enables data transfers to be performed between memory and a register without CPU intervention. This capability shortens transfer-processing time and reduces the load on the CPU, making more computing time available for executing application code.  The DTC is based on the highly rated design used in the high-performance MCUs in the 16-bit H8S series and the 32-bit H8SX series.

The R8C/Tiny chips incorporate a power-on reset (POR) function that places all on-chip circuits in the reset state when the MCU is turned on. However, the revised POR circuit in them has been upgraded for extra flexibility and can now handle a slower ramp-up of the power supply voltage. Like the other R8C/Tiny MCUs, the devices have a single-pin debugging interface that lets system engineers use the Renesas E8a emulator/on-chip debugger as a development environment — even while all I/O pins are in use — for efficient program development.

The new MCUs have an additional debugging function that allows developers to make RAM references and changes during user program execution, a capability that can improve debugging efficiency. The E8a emulator retains its capability as a code writer for the MCU's on-chip flash memory.

Besides the E8a emulator/debugger, Renesas offers a comprehensive set of hardware and software development products for systems that use R8C/Tiny MCUs. Additional support is available from a large international community of third-party suppliers. Renesas plans to offer support for the E100 full-spec emulator for situations requiring a more powerful debugging tool. The company also will continue to extend the R8C/Tiny line-up for automotive applications with microcontrollers offering improved performance and functions. 
More informtion: www.renesas.com

Read more ...

Toshiba Electronics TB6588FG evaluation board speeds motor drive development

Toshiba Electronics Europe has expanded its family of motion control development platforms with a new evaluation board that will speed implementation of sensorless drives for three-phase brushless DC (BLDC) motors. The board is ideal for testing and prototyping drives for motion control applications requiring motor bridge voltages ranging from around 10V to 42V.

Based around a Toshiba PWM sensorless driver ASSP, the new TB6588FG evaluation board allows engineers to modify key parameters that adjust start-up performance, motor efficiency and acoustic noise. The board is designed for direct control by voltage input or connection to a host processor, and connects directly to the motor under test with no additional hardware components. Target applications include home appliance, pump, industrial and automotive motion control designs.

At the heart of the board is Toshiba's TB6588FG PWM sensorless driver ASSP (application specific standard product). This IC brings together PWM sensorless motor control, protection functionality, an output power stage and an operational amplifier in a single 36-pin HSOP package.

By combining sensorless operation with high levels of on-board functionality, the ASSP significantly reduces the component count, design complexity and development time of three-phase, full wave BLDC motor applications with power levels up to 60W.

The TB6588FG is a complete motor driver system that controls forward or reverse rotation speed by changing the PWM duty cycle based on an analogue control signal input. Full wave PWM operation provides for high-efficiency and low-power operation while minimising electrical and acoustic noise. Lead angle control options of 0º, 7.5º, 15º and 30º allow designers to tune their application for optimum efficiency.

More information: www.toshiba-components.com

Read more ...

Tuesday, July 15, 2008

Quebec's EXFO develops industry-first carrier Ethernet test products

EXFO Electro-Optical Engineering Inc., Quebec, has developed test enhancements for its FTB-8510B/G and IQS-8510B/G Packet Blazer Gigabit Ethernet (GigE) and 10 Gigabit Ethernet (10 GigE) test modules.

These now support Provider Backbone Bridge - Traffic Engineering (PBB-TE) and Internet Protocol, Multi-Protocol Label Switching (IP/MPLS) functionalities in a single module, allowing network service providers (NSPs) and network equipment manufacturers (NEMs) to fully validate carrier Ethernet services and network equipment.

"Our Packet Blazer test modules continue to evolve with market needs through the industry’s first field-test solution that supports PBB-TE and MPLS and strengthens the ability of NSPs to expand their Ethernet infrastructures in a cost-efficient, quality-assured manner," Etienne Gagnon, EXFO Vice-President Product Management and Marketing, says. "The successful deployment of Ethernet services depends on carrier-grade scalability, reliability and quality of service (QoS). PBB-TE and IP/MPLS are two choice technologies enabling NSPs to efficiently deploy Ethernet services with high levels of configurability and resiliency."

The new software also introduces a number of testing features, including support for advanced multi-stream traffic filtering techniques and 1X and 2X Fibre Channel testing. These new capabilities on the FTB-8510B/G, combined with full-line rate TCP throughput testing and bi-directional RFC 2544 measurements, offer NSPs a comprehensive and portable tool for deploying, maintaining and troubleshooting next-generation Ethernet services, EXFO says.

The modules, designed for portable field-test applications, are compatible with the FTB-200 Compact Platform and more advanced FTB-400 Universal Test System. The IQS-8510B/G modules, purpose-built for manufacturing and R&D test applications, are hosted inside the IQS-500 and IQS-600 platforms. All of these platforms support a wide range of additional test modules, including optical, transport and datacom, at various transmission rates reaching up to 43 Gbit/s, EXFO says.

The firm says it is the second-largest provider of portable test and measurement products in the global telecommunications industry and is positioning itself in next-generation network (NGN) testing and monitoring applications.

Its Telecom Division, which represents about 85% of the company's business, provides a full suite of test products and monitoring systems to network service providers, cable-TV operators, and network equipment and component manufacturers.

Read more ...

Multi-Channel Transceiver Offers 5-km Range

With a 500-mW (+27 dBm) RF output power and a receiver sensitivity of –118 dBm (for 12 dB SINAD), the BHX2 multi-channel narrowband transceiver sports a range of up to 5 km. Standard operating frequency is 458.5 to 459.1 MHz, but factory-tuned custom versions can cover any 5 MHz switching band between 420 and 480 MHz. The transceiver's 25-kHz channel spacing allows a total of 128 channels, configurable via an RS-232 interface. Using a supply voltage of 5.5 to 15 V, the BHX2 draws 350 mA while transmitting and 30 mA for receiving. The module offers a 5-kbit/s data rate and incorporates a 1200-baud half-duplex modem that is compatible with that used by the company's other devices. An automatic noise squelching function activates when there is no RF at detectable levels or when the non-coherent noise is high enough to block out weak signals. The module comes in an 85- by 39- by 13-mm package and conforms to both the EN 300 220-3 and EN 301 489-3 standards. RADIOMETRIX LTD., Harrow, UK. +44 (0) 208-909-9595.

Product URL: Click here for more information
Read more ...

L-Band VCO Features Low Second-Harmonic And Phase Noise

Operating in the L-band from 1560 to 1580 MHz, the CLV1570B-LF voltage-controlled oscillator (VCO) is well-suited for microwave radio applications that require superior second-harmonic suppression and very low phase noise. The device's tuning voltage range is 0.5 to 4.5 V dc. It has a typical phase noise of –108 dBc/Hz at a 10-kHz offset and a typical tuning sensitivity of 25 MHz/V. Second-harmonic suppression is typically –25 dBc. The VCO uses a 5-V dc supply, drawing 24 mA (typical) over a –40°C to 85°C range. The RoHS-compliant CLV1570B-LF comes in the company's industry standard MINI package with low shield measuring 0.50" by 0.50" by 0.13". It is available in tape-and-reel packaging for production requirements. The CLV1570B-LF is also well suited for automated surface-mount assembly and reflow soldering. Z-COMMUNICATIONS INC., San Diego, CA. (858) 621-2700.

Product URL: Click here for more information
Read more ...

Allegro MicroSystems Europe A4935 automotive-grade 3-phase MOSFET pre-driver IC

The A4935 is targeted at the rapid growth in 3-phase brushless DC motor applications in the automotive and industrial sectors.

This third-generation device includes enhanced performance and operational features, and is ideal for systems that use sinusoidal control of the motor phase currents. This commutation method provides smooth operation, reducing audible noise and minimising torque ripple at the load.   

The new device integrates a regulating charge pump which provides full gate drive capability for battery voltages down to 7 V and reduced gate drive for battery voltages as low as 5.5 V.

Also included are performance enhancements of the current sense amplifier, as well as better fault diagnostics and reporting to decode and identify faults. Features such as top-off charge pump and bootstrap charge management make the A4935 much easier to manage in terms of ensuring an adequate bootstrap capacitor charge under varying PWM conditions.

Other features include cross-conduction protection with adjustable dead time and a low-current 'sleep' mode.

The A4935KJP-T is supplied in a small-footprint 48L eLQFP small profile thermally efficient exposed-pad package which is lead (Pb) free with 100% matte tin leadframe plating.

More information: www.allegromicro.com

Read more ...

Monday, July 14, 2008

Tantalum capacitor achieves new CV ratings

High-capacitance cathode construction designed for harsh environments

The TWA wet electrolytic tantalum capacitor features a patented high-capacitance cathode construction that enables previously unavailable CV ratings of 2,200 µF at 25 V and 1,000 µF at 60 V — exceeding the values specified in the MIL-PRF-39006 shock and vibration standard. With a welded tantalum can and header assembly providing a hermetic seal in harsh environments, the capacitor operates in temperatures from –55° to 125°C.

The capacitor is available in a variety of case sizes and ratings, including a T1, A case offering up to 10 µF at 125 Vdc through a T4, E case offering up to 150 µF at 125 Vdc. Custom capacitance and voltages are also available. (From $35 ea/50 — available now.)

AVX, Myrtle Beach, SC
Dan Lane 843-946-0483
Read more ...

Rohde & Schwarz application firmware for Wimax MIMO measurements

Rohde & Schwarz has added a suite of application firmware for Wimax MIMO measurements in line with IEEE 802.16e-2005.

The FSQ-K94 option is designed to run on the FSQ and FSG signal¬ analysers. It also supports a combination of several analysers for testing up to 4x4 MIMO systems.

The application firmware can be used for testing semiconductor components such as Wimax MIMO chipsets, amplifiers and mixers, as well as complete products such as Wimax basestations or pico stations.

A large number of measurements required for testing MIMO systems can be performed by means of a single vector signal analyser. To test the interaction between the individual components, however, two instruments may sometimes be required.

In this case, the user can combine several R&S FSQ or R&S FSG analyzers to create a flexible test solution made up of standalone signal analyzers for testing 4x4 MIMO
systems, for example.

See http://www.press.rohde-schwarz.com

Read more ...

Saturday, July 12, 2008

Alpha Micro MatchPort b/g Pro for remote secure control

Alpha Micro Components has added the MatchPort b/g Pro to its line of networking products.

The MatchPort b/g Pro allows a range of machines to be managed and controlled remotely over a network with an added level of security.

The secure embedded WiFi networking module features SmartRoam that continuously tracks the radio signal strength of access points within range. Pre-authentication and caching enables smooth and automatic transition to an access point with a stronger signal, enhancing mobile reliability while minimising communication disruption for the user.

MatchPort b/g Pro handles the most computationally demanding or data intensive applications effortlessly with a 32-bit, 159 MIPS (Dhrystone 2.1) 166MHz processor.

With 8 MB of SDRAM and 8 MB flash, it provides enough memory capacity for OEM customisation, loading web pages, and data 'store and forward' applications.

It features two serial input ports with 230kbit/s data rate capability, seven control pins (CP/GPIO), and a wide operational temperature range of -40 to 70 deg C, with the option to operate up to 85 deg C with lower MTBF (mean time between failures).

See http://www.alphamicro.net

Read more ...

Friday, July 11, 2008

High Reliability Tantalum

With the commercial power supply market increasingly aware of the need to minimize failure rates, as more of these products are being designed into high-end systems, demand has risen for different levels of enhanced-reliability, low ESR capacitors. In response, AVX has introduced a range of products within its TRJ professional series tantalum chip which can deliver significantly lower ESR while achieving reliability levels (0.5%/1000hours) twice that of standard tantalum devices. The capacitors are available in EIA standard A, B, C, D and E case sizes in voltages ranging from 6.3 to 50V and capacitance values from 0.1 to 470µF
Read more ...

Maxim quad and dual sink-source current DACs for power-supply adjustment

Maxim has introduced quad and dual sink-source current DACs specifically designed for power-supply adjustment, the DS4422 and DS4424.

Both are I2C-controlled with 7bit current DACs designed to control a DC-DC converter by sinking or sourcing current directly into the power supply's feedback node. "This control technique allows existing power-supply designs to be margined and adjusted with minimal redesign, making the devices ideal for servers and video processing cards," claimed the firm.

The chips power-up with their outputs open circuit to allow the power-supply feedback resistors to perform naturally. This removes the need to address the chip immediately at start-up.

DAC full scale output current is programmed between 50 and 200µA with an external resistor with ±six per cent accuracy.

The I2C bus can then be used to linearly set the output currents to any of the 127 sink or 127 source steps up to the maximum value.

Two address inputs allow up to four devices or sixteen separate supplies to be controlled on a single I2C bus.

The DS4422 (two DAC) and DS4424 (four DAC) are specified over -40 to +85°C and come in a 3x3mm 14pin TDFN package.

See http://www.maxim-ic.com

Read more ...

Supertex Class-D driver for high power audio amplifiers

Californian high voltage chip firm Supertex has introduced a Class-D driver for high power audio amplifiers.

"The MD7120 has been optimised for parameters critical to Class-D audio performance such as high efficiency and low EMI," said marketing v-p Ahmed Masood.

"Additionally, this Mosfet driver provides up to a 3.A peak driving current with matched output resistance and channel-to-channel propagation delay for lower total harmonic distortion and noise."

Powered from between 200V and 12V, amplifiers can be built with over 100W output with 90 per cent efficiency.

Dead time matching is ±5ns with rise or fall times under 30ns into a typical 1nF load. Four N-channel output mosfets are required, driven from normal logic level inputs by directly coupled internal level translators.

On-chip is control logic, level translators, a bootstrap-powered high side gate driver and over-temperature, under-voltage and current protection circuits.

"The thresholds of the current protection for both the high and low sides are resistor-programmable," said Supertex.

An associated application note AN-H61 (PDF) describes demo board with a self-oscillating 750kHz second-order modulator using the driver. The board delivers 50W into 8Ω with 0.01 per cent THD+noise from ±35V. Claimed efficiency of the power stage is over 80 per cent at 10 to 20W.

See http://www.supertex.com

Read more ...

Nanoscale Lithographic Technology: Finer Lines For Microchip

MIT graduate student Chih-Hao Chang of the Department of Mechanical Engineering demonstrates the absence of light diffraction from a frequency-doubled grating on a 100 mm-diameter silicon wafer. The wafer is immersed in water to enable blue-light optical diffraction from the 200 nm-period 'master' grating at the periphery of the wafer, whilst the center of the wafer, where the grating has a 100 nm pitch, exhibits no optical diffraction. Mr. Chang is standing in front of the MIT nanoruler tool which produced the patterns. (Credit: Image courtesy of Massachusetts Institute of Technology)

Their new technique could pave the way for next-generation computer memory and integrated-circuit chips, as well as advanced solar cells and other devices.

The team has created lines about 25 nanometers (billionths of a meter) wide separated by 25 nm spaces. For comparison, the most advanced commercially available computer chips today have a minimum feature size of 65 nm. Intel recently announced that it will start manufacturing at the 32 nm minimum line-width scale in 2009, and the industry roadmap calls for 25 nm features in the 2013-2015 time frame.

The MIT technique could also be economically attractive because it works without the chemically amplified resists, immersion lithography techniques and expensive lithography tools that are widely considered essential to work at this scale with optical lithography. Periodic patterns at the nanoscale, while having many important scientific and commercial applications, are notoriously difficult to produce with low cost and high yield. The new method could make possible the commercialization of many new nanotechnology inventions that have languished in laboratories due to the lack of a viable manufacturing method.

The MIT team includes Mark Schattenburg and Ralf Heilmann of the MIT Kavli Institute of Astrophysics and Space Research and graduate students Chih-Hao Chang and Yong Zhao of the Department of Mechanical Engineering. Their results have been accepted for publication in the journal Optics Letters and were recently presented at the 52nd International Conference on Electron, Ion and Photon Beam Technology and Nanofabrication in Portland, Ore.

Schattenburg and colleagues used a technique known as interference lithography (IL) to generate the patterns, but they did so using a tool called the nanoruler--built by MIT graduate students--that is designed to perform a particularly high precision variant of IL called scanning-beam interference lithography, or SBIL. This recently developed technique uses 100 MHz sound waves, controlled by custom high-speed electronics, to diffract and frequency-shift the laser light, resulting in rapid patterning of large areas with unprecedented control over feature geometry.

While IL has been around for a long time, the SBIL technique has enabled, for the first time, the precise and repeatable pattern registration and overlay over large areas, thanks to a new high-precision phase detection algorithm developed by Zhao and a novel image reversal process developed by Chang.

According to Schattenburg, "What we're finding is that control of the lithographic imaging process is no longer the limiting step. Material issues such as line sidewall roughness are now a major barrier to still-finer length scales. However, there are several new technologies on the horizon that have the potential for alleviating these problems. These results demonstrate that there's still a lot of room left for scale shrinkage in optical lithography. We don't see any insurmountable roadblocks just yet."

The MIT team performed the research in the Space Nanotechnology Laboratory of the MIT Kavli Institute of Astrophysics and Space Research, with financial support from NASA and NSF.

Adapted from materials provided by Massachusetts Institute of Technology.

Read more ...

Wednesday, July 09, 2008

Silicon Storage 8051-based MCU with two system management buses

Silicon Storage Technology has added to its FlashFlex family of 8-bit microcontrollers with its first 8051-based MCU to feature two system management buses (SMBus), each supporting up to 400kbit/s data throughput, in a 6x6mm QFN package.

The SST89C58RC supports operating voltages from 2.7V to 5.5V.

According to the supplier, the dual hardware SMBus interfaces let the SST89C58RC act as an intermediary between a host processor and a complex multi-chip A/V subsystem.

The MCU is suitable for bundled applications, shielding the host from low-level interrupts while providing it with a 'virtual' register interface for simplified control and status access.

The SST89C58RC comes with 1kbyte of on-chip RAM and up to 34kbyte of embedded SuperFlash memory.

See http://www.sst.com

Read more ...

Fairchild Semiconductor FOD07xx Series high speed logic gate Optocoupler

Fairchild Semiconductor brings designers optocoupler devices that deliver a fast and robust isolation interface to ensure low transmission error rates and proven reliability for noisy industrial environments.

The FOD0721, FOD0720 and FOD0710 are logic gate optocouplers that isolate the logic control circuitry from the transceiver at the bus interface level. Since industrial systems are susceptible to noise transients, FOD07xx's high noise immunity coupled with its high speed (25Mbps) minimises the chance of transmission errors or system failures. These products meet high reliability requirements and are qualified according to the UL1577 standard. The FOD07xx series is ideal for industrial communication standards such as Profibus, DeviceNet, CAN and RS485.

The FOD07xx series are packaged in Fairchild's patented Optoplanar co-planar packaging, which claims to reduce package capacitance by more than 30 per cent compared to other products. This low capacitance package leads to a guaranteed 20kV/µs minimum Common Mode Noise Rejection rating that is double that of alternative products, allowing the FOD07xx series to operate in noisy industrial environments. 

The FOD07xx series is part of Fairchild's optoelectronic portfolio that includes high-speed optocouplers, gate drive optocouplers, snubberless triac driver, photo transistors, and infrared components. The FOD0721, FOD0720 and FOD0710 use lead-free (Pb-free) terminals and have been characterised for moisture sensitivity in accordance with the Pb-free reflow requirements of the joint IPC/JEDEC standard J-STD-020.

All Fairchild's products are designed to meet the requirements of the EU's directive on the restriction of the use of certain substances (RoHS).

Price (each 1000pcs):

  • $2.67 for FOD0721
  • $2.44 for FOD0720
  • $2.21 for FOD0710


Samples are available now with delivery 6 weeks ARO

More information: http://www.fairchildsemi.com.

Read more ...

Renesas Technology high-frequency power MOSFETS

Renesas Technology's latest high-frequency power Mosfets, designed for use in the transmitter power amplifier of handheld wireless equipment, the devices achieve 60% added power efficiency in the RQA0010 at 3.6V and 55% in the RQA0014.

In particular, when a two-stage amplifier is implemented by driving the RQA0010 with the output of the RQA0014, the circuit achieves the industry's highest level of performance: a 1.2W output at 3.6V.

With high ESD immunity, the devices maintain their high-efficiency characteristics at 20kV and over and achieve ESD immunity level 4. 

The ESD immunity level is measured with a test that verifies that a static aerial discharge applied to the antenna of a wireless device does not affect that device and that simulates the discharges that actually could occur from a person or metal object as required by the IEC61000-4-2 standard.

The following levels are stipulated by this standard. Level 1: 2kV, level 2: 4kV, level 3: 8kV, level 4: 15kV.

The RQA0014 is mainly for use as a transmitter power amplifier driver and the RQA0010 is suitable for use as a power amplifier.

See http://www.renesas.eu

Read more ...