Power Electronics


Wide Body Fans A new series of 127 mm brushless dc cooling fans provides the airflow and capabilities of many large format 170 mm units, while using 30% less space. Fans in the Widebody TA500DC series supply 190 CFM from 2-in.-wide housings and operate at static pressure of up to 0.68 inwg. These 5-in.22-in. fans have operating voltage ranges centered on 12V, 24V, or 48V. Premium performance models in the series offer 31 operating voltage ranges and constant fan speed over broad segments of those supply ranges. Nidec, Canton, Mass.

Dual-Well Fixture A Dual-Well fixture for use in high-volume testing of power supplies offers increases in test productivity, by allowing one unit to be tested while the other is replaced. Combining Interpro 9000 ATE with PowerStart 5 software reduces test times for simple dc-dc converters to just a few seconds. Schaffner EMC Inc., Edison, N.J.

Digital Oscilloscopes Four new Waverunner-2 series instruments feature a 350 MHz to 500 MHz bandwidth, higher sampling rate (1-4 GS/s), and longer memory (up to 8 Mpts). They incorporate Wavepilot[TM] and QuickZoom features for easy access to signal measurements. LeCroy Corp., Chestnut Ridge, N.Y.

Slim Power Relay The new Slimpak[TM] AZ961 p. c. board-mount relays are for applications where real estate is at a premium. It can switch up to 5A, and has dielectric strength of 2kV and 4kV surge withstand capability from contact to coil. The variety of contact arrangements (SPST, SPIDT) and sensitive coils offer flexibility when designing scalable systems. It's available with an epoxy seal and packaged in tubes. American Zettler, Inc, Aliso Viejo, Calif.

Ultra-Small LDOs The ZXCL series of low dropout regulators (LDOs) is for use in low-power and space-critical applications. The LDOs are available in the ultra-small SC70 package (2 mm21.25 mm21.0 mm). Output current of up to 150mA matches the performance of larger SOT23 alternatives. Quiescent current is 25A, providing valuable power savings for portable and battery-powered applications. Power consumption is also reduced by a shutdown mode that consumes less than 1A. Output voltages of 2.6V, 2.8V, 3.0V, and 3.3V meet the needs of a wide range of applications. Zetex Inc., Commack, N.Y.

Ultra-Low-Voltage Power Supervisors The MIC2774 and MIC2777 feature a choice of preprogrammed voltage options and quiescent current. The MIC2774 has an industry-standard pinout with a dedicated manual reset input and a choice of output. The MIC2777 features both active-high and active-low reset outputs. Micrel, Inc., San Jose, Calif.

SMD Pulse Capacitor The SPC series of SMD capacitors, made of double-metallized PPS film, offers low ESR. The 2824 SMD package handles high-frequency ac currents and pulses. The capacitor is ideal for snubbing and power factor correction in SMPS and other applications requiring the handling of pulses or high-frequency ac. Its wound, encapsulated design is free from the risk of delamination during or after assembly. It's rated for 630Vdc (350Vac) in capacitance values from 470 pF to 4700 pF. Evox-RIFA, Lincolnshire, Ill.

Surface Mount Trimmers SURFTRIM[R] GKP6R066 has a capacitance range of 2.5 pF to 6.0 pF with drift after setting of less than 51%. Q is 200 minimum at 1 MHz. The temperature coefficient of capacitance is NPO 5500 ppm/C for GKP6R066. Operating temperature range is 125C to 85C. Voltage rating is 25Vdc and dielectric withstanding voltage is 55Vdc. Sprague-Goodman, Westbury, N.Y.

Relays Rated to 1 GHz The TO-5 is a high performance relay used in telecommunication, computer test equipment and other high frequency applications. It now carries a 1 GHz rating offering a compact switching solution. The TO-5 relay has excellent signal isolation, stable insertion loss and low VSWR. The TO-5 relay is positioned to deliver high-frequency switching in high-volume and cost-sensitive designs. CII Technologies, Inc., Asheville, N.C.

High-Voltage IGBTs These new IGBTs have rated blocking voltages of 900V to 1200V, with faster switching times and lower saturation voltages. In the 900V class are the 24A IXGH12N90C and the 56A IXGH28N90B. At 1000V is the new 30A IXGP15N100C. There are two 1200V types, the 30A rated IXGH15NI20C and the 70A rated IXGH35NI20C. All types are available with an anti-parallel, ultra-fast, reverse recovery FRED diode. IXYS Corporation, Santa Clara, Calif.

High-Voltage RF MOSFETs Rugged high-voltage RF MOSFETs address the needs of demanding power electronic systems. They employ a new process producing RF amplifier MOSFETs with double the available SOA (Safe Operating Area). They are available in the common source TO-247 packages, in mirror-image A and B configuration. Typical operating voltage for the 500V ARF460A/B is 150V, 300V for the 1kV ARF461A/B. The rated power dissipation is 250W with an Rq subscript J-C of 0.5C/W. Advanced Power Technology, Bend, Ore.

Surge Protectors These totally integrated surge protectors (TISPs) provide protection for telecommunications equipment in instances where high voltages occur. Under a system fault condition, the TISP limits overvoltages to a safe level, allowing all current to pass through it and protecting electronics from harmful voltages. These products are available in single to quadruple configurations. Fixed voltage protection ranges from 72V to 400V, and programmable voltage protection ranges to 1120V. Bourns, Inc., Riverside, Calif.

New 240Vac Variable Transformers The POWERSTAP 12C Series of variable transformers is offered in 240Vac single- and 3-phase manually operated, open-construction models that are designed for back of panel mounting. The new tapping arrangement permits an output voltage of zero to line voltage or to 10% above line voltage. Superior Electric, Bristol, Conn.

New Fans Cool Systems OptiFans[TM] meet thermal management needs in the smallest personal computers and electronic enclosures to massive telecom and industrial equipment environment. Noise emitted from fan bearings is minimized by proper bearing selection and mounting techniques. They're flow tested in a dedicated fan-testing chamber. Some models provide optional internal speed control that varies fan airflow based on the temperature of the ambient air. Aavid Thermal Technologies, Inc., Concord, N.H.

DIN Power Connectors The type H11 20A/pin DIN power connector line supplies 500V over 11 contacts, providing an additional 5A/pin compared to the standard H15 solution. The male connector has faston or right-angled terminations, and the female has straight pins, faston, or press-fit terminations. The slimline version has the same specifications as the standard connector - but saves up to 985 sq mm on the board. 2E SysCom, Waltham, Mass.

Plug-In Power Modules These 1.5A and 3A power modules provide power solutions for applications using digital signal processors, microprocessors, integrated circuits and field programmable gate arrays. Suited for servers, workstations, and networking applications, they interface with TMS320C5000[TM] and TMS320C6000[TM] DSP platforms. Texas Instruments, Warrenville, Ill.

Surface Mount Inductors Open-frame, self-leaded, surface mount DR338 Series of inductors is space and cost-efficient for dc-dc converter and switching power supply applications. It features a low-profile and flattop design, with an inductance range from 10H to 470 H (520%), and a rated current from 3.6A to 0.53A. Datatronics Romoland, Inc., Romoland, Calif.

Folded-Fin Heat Sinks Using new folded-fin technology to maximize surface area, these heat sinks increase the flow of heat from the chip to the air. Brazed attachment of the fins to the base eliminates any chance of cracks forming. Therma-Fin's[TM] thermal performance allows the fan to run at a lower speed for quiet operation and increased reliability. Thermacore, Lancaster, Pa.

New MOSFET Package PowerPAK[TM] packaging technology enables devices with thermal resistance of ,1C/W. Thermal resistance is 16C/W for a single-channel, standard SO-8. They provide a direct thermal path from the backside of the copper die attach pad to the p. c. board. Siliconix Inc., Santa Clara, Calif.

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