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Maxim Integrated Products introduces the MAX6495 through MAX6499 overvoltage protection circuits that operate as a switch controller to either disconnect or limit the output voltage to a load during an overvoltage condition. The circuits turn off an external n-channel MOSFET with an internal 100-mA pulldown current when the monitored voltage exceeds its overvoltage threshold. These low-power devices consume only 20 µA of quiescent current and operate from 5.5 V to 72 V.
The MAX6497 features a latch-off mode that disables the MOSFET until the power or shutdown input is cycled. These protection circuits are offered in a 3-mm × 3-mm TDFN package. Prices for these devices start at $1.23 each in quantities of 1000.
Maxim Integrated Products
Multiphase Core Controller
Intersil's ISL6316 is a high-performance pulse-width modulation (PWM) CPU multiphase core controller for Intel-based voltage-regulator down (VRD) 10.X and enterprise voltage-regulator down (EVRD) 10.X desktop, workstation and server motherboards. The four-phase ISL6316 is an accurate CPU core controller and includes thermal monitoring and tracking overcurrent protection (OCP) over temperature, with ±0.5% accuracy over the complete CPU voltage range. The temperature thresholds of the SL6316 are programmable to enable the controller to signal the CPU to reduce its power consumption.
The ISL6316 is available now in a 40-lead QFN standard or lead-free package and is priced at $2.55 each in 1000-unit quantities.
TT electronics' IRC Wirewound and Film Technologies Division has developed a “tight-pitch” version of its open-air metal-element current-sense resistor, designated the OAR-TP Series, with ratings as high as 3 W in a reduced printed-circuit board footprint. The resistor's footprint is reduced by extending the height of the device above the board, thus keeping the resistor element's “hot spot” safely off the printed-circuit board and providing for increased air circulation under it, which in turn provides increased heat dissipation and cooler operation.
The OAR-TP Series resistors are rated for 1 W or 3 W at 85°C, with resistance values from 0.1 Ω to 0.005 Ω, with tolerances down to ±1%. They feature TCRs as low as ±20 ppm/°C and inductance values in the single-digit nano-Henry range. Typical pricing for the OAR-TP Series resistors ranges from $0.18 to $0.20 each in quantities of 25,000.
Synchronous Switching Controller
National Semiconductor's LM1770 is a synchronous buck switching controller for low-voltage dc-dc conversion. This efficient controller utilizes constant on-time control. The LM1770, packaged in the tiny SOT23-5, provides low-voltage point-of-load regulation from standard 5-V and 3.3-V rails in space-constrained applications.
The synchronous operation of the high-side PFET and low-side NFET in the LM1770 results in reduced power dissipation. The input voltage range is from 2.8 V to 5.5 V, and the output voltage can be set as low as the reference voltage, 0.8 V. The LM1770 is priced at 95 cents each in quantities of 1000.
Santa Clara, Calif.
Miniature Battery Chargers
Semtech has unveiled the SC805 and SC806 ultrasmall battery-charger devices designed for consumer electronics applications. The SC805 and SC806 are fully integrated devices, including charger, FET pass transistor, reverse-blocking diode, sense resistor and thermal protection. In addition to charging Li-ion or Li-polymer batteries, the devices can work as general-purpose current sources or as current sources for charging NiCd and NiMH batteries. The drain current on the battery in shutdown or monitor modes is only 0.1 µA, and overcurrent protection is provided in all charging modes.
The lead-free package design complies with the European Union's Restriction on Hazardous Substances in Electrical and Electronic Equipment (RoHS) directive. Both devices are packaged in 3-mm × 3-mm thermally optimized MLP packages. Pricing in 10,000-piece lots is $1.05 each for the SC805 and $1.01 each for the SC806.
Zetex Semiconductors has announced the ZXCT1011 current monitor with a wide input voltage range from 2.5 V to 20 V and the ability to withstand circuit transients.
The device assures accurate measurement of dc currents over the temperature range of -40°C to 125°C. The five-pinned ZXCT1011 measures the voltage across a low-value sense resistor and converts it into a proportional output current via an external shunt resistor. The current is scaled by an output resistor to produce a 1%-accurate ground-referenced output voltage. A maximum sense voltage of 500 mV and a bandwidth of 1.5 MHz assures that the current monitor provides accurate monitoring of supply of load current in real time, over a wide range of load currents from microamps to hundreds of amps.
The ZXCT1011 costs $0.58 each in quantities of 10,000.
Stackpole Electronics has introduced a new series of power choke inductors. Designated the PCMC Series, this inductor provides design engineers with high saturation currents and operational frequencies, as well as low losses due to DCR, in a low-profile shielded SMD package. With sizes ranging from 13.8 mm × 12.6 mm to 7.3 mm × 6.5 mm, with profiles as low as 3 mm, the PCMC Series is ideal for dc-dc conversion in portable devices.
Inductance values for the PCMC Series range from 0.10 µH up to 4.7 µH, with DCR as low as 0.68 mΩ, and dc current capability of up to 55 A. Standard tolerance for this product is 20%; tighter tolerances are available. The PCMC Series is RoHS compliant with lead-free 100% matte tin terminations.
Advanced Analogic Technologies has introduced two new 1-MHz stepdown converters. Available in an extremely small 2.0-mm × 2.1-mm SC70JW-8 package, the AAT1123 and AAT1143 supply 600 mA and 400 mA max output current, respectively, while maintaining a low 25-µA no-load quiescent current.
Both the AAT1123 and AAT1143 support an input voltage range of 2.7 V to 5.5 V and an output voltage as low as 0.6 V. The devices are available in either a fixed version with internal feedback or a programmable version with an external feedback resistor. Their 1-MHz switching frequency helps minimize external component size while keeping switching losses to a minimum. The AAT1123 also features a fast 100 µs (typical) turn-on time. Efficiency levels for the AAT1123 and AAT1143 range up to 97% and 95%, respectively. The AAT1123 and 1143 devices sell for $1.09 and $0.92 each, respectively, in 1000-piece quantities.
Technologies Sunnyvale, Calif.
Ruggedized DC-DC Converters
Absopulse Electronics has recently expanded its DCW Series of dc-dc converters, adding two wide input voltage ranges and increasing output power up to 200 W. These converters are available with either a 20-Vdc to 60-Vdc input range, or with a 65-Vdc to 160-Vdc input range. They deliver 100 W, 150 W or 200 W, with standard output voltages of 12 Vdc, 24 Vdc, 48 Vdc or 125 Vdc. Other output voltages also are possible. Designed for operation in rugged industrial environments, additional conformal coating or full encapsulation options ensure immunity to the high levels of shock, vibration, humidity, moisture and airborne contaminants typically encountered in railway and other extreme environments.
The DCW100 is priced at $98 each, the DCW150 at $123 each and the DCW200 at $169 each, in quantities of 100.
Switching Power Supplies
Emerson Network Power, a business of Emerson, has announced the addition of five new models to the popular high-density 3 × 5 LPS120 switching power supply family from Astec Power. At 6.7 W/cu in., the units will deliver up to 130 W of total power with output voltages of 3.3 V, 12 V, 15 V, 24 V and 48 V, in addition to the 5-V output offered by the recently introduced LPS122 model.
The units can deliver their full-rated output of 130 W with 30 CFM forced air or 80 W with convection cooling. Featuring active power-factor correction to minimize input harmonic distortion, the LPS120 Series' compact 85-Vac to 264-Vac power supplies are ideal for 1U (1.75-in.) rack installations and other low-profile applications. All models also offer a 12-V, 0.5-A auxiliary output and a 5-V, 0.5-A standby output, as well as overload, overvoltage and thermal protection.
Samples of the new models are available now with prices starting at $95 in OEM quantities.
LED Driver Circuit
Power Integrations' driver circuit for off-line LED lighting, called the DI-92, requires only nine components to deliver 40 mA of current and 0.5 W of output power — an ideal level for emergency exit signs, nightlights and a variety of other lighting applications. LNK302, the power-conversion IC featured in DI-92, is a member of Power Integrations' LinkSwitch-TN family of ICs, which are ideal for use in low-power applications not requiring safety isolation. LinkSwitch-TN products integrate a 700-V power MOSFET, oscillator, simple on/off control scheme, frequency jittering to reduce EMI, as well as safety features such as short-circuit protection, hysteretic thermal shutdown and open-loop protection.
The DI-92 is available for download from the Design Examples page of Power Integrations' website.
San Jose, Calif.
Linear Technology has announced a new family of CMOS amplifiers with input dc characteristics similar to precision bipolar amplifiers. The LTC6078 and LTC6079 quad op amps have a maximum input offset voltage of 25 µV, and guaranteed offset voltage drift is 0.7 µV/°C max while drawing only 55 µA of quiescent current per channel.
The input voltage noise is 19 nV/√Hz. This implies a tenfold reduction in power consumption over existing op amps with similar dc accuracy.
LTC6078 dual is offered in the 8-pin MSOP and 3-mm × 3-mm DFN packages. The LTC6079 quad is available in the 16-pin SSOP and 5-mm × 3-mm DFN packages.
Pricing for 1000-piece quanitities starts at $1.49 each for the LTC6078 dual and $2.53 each for the LTC5079 quad.
AC-DC Medical Converters
Power supply specialist XP Power has introduced a low cost, space-saving 15-W ac-dc converter with a footprint of 2.75 in. × 1.89 in. It saves 20% board space over equivalent parts from other manufacturers and is designed to eliminate the need for external power supplies in many applications. The CU15-M is an open-frame switcher with 4000 VAC input-to-output isolation. It is printed circuit board (PCB) mounted and is less than 1 in. high. The power supply delivers single outputs from 3.3 VDC to 24VDC (adjustable ±5%) from a 85-264 VAC input. The CU15-M has dual input fuses — line and neutral - and its UL60601-1 and EN60601-1 medical safety approvals make it faster and easier for OEMs to gain approval of their end equipment. The Class II approved power supply also meets Level B EMC standards. The units have 0.5% line regulation, and 1% load regulation from 10% load to full load. Ripple and noise are limited to 1%peak-to-peak. Comprehensive over-voltage and short-circuit protection is built in. With up to 82% efficiency, the power supply is convection cooled and operates from 0 °C to +70 °C ambient, with de-rating above +50 °C. It features high peak load capability, typically 50% above the nominal load for up to 30 seconds at 10% duty cycle. The CU15-M is available from stock. Special output voltages are available to order. Pricing is from $21.00 each based on 1000 pieces.
ENGINEERING MATHEMATICS SOFTWARE
Maplesoft announced today the availability of Advanced Engineering Mathematics with Maple. This Maplesoft release is the first electronic, interactive version of Advanced Engineering Mathematics. Advanced Engineering Mathematics with Maple provides complete coverage of all major areas of engineering mathematics. A Solution Manual that contains full solutions to many exercises in the e-book is also available.
Advanced Engineering Mathematics with Maple features nine major subject areas, 48 chapters and 273 section topics. The e-book includes modifiable examples and interactive graphs throughout. The text provides a logical arrangement of topics with many short self-contained sections for easy, direct access. Concepts are stated and explained clearly before, rather than after, the mechanical calculation techniques are introduced, resulting in quicker comprehension of the important ideas. It includes many real-world applications of interest to engineers selected from a wide spectrum of physical and mathematical disciplines. The e-book features more than 7000 exercises, including section exercises and chapter review questions. Answers are provided to selected exercises. Advanced Engineering Mathematics with Maple is currently available for a special introductory price of $99. Maple 10 is also available directly from the Maplesoft Web Store.
Quadruple Output DC/DC Converter
Beta Dyne, Inc. has announced its lineup of dc-dc converters. The BD16000 is a 15-W four-output low-Noise dc-dc converter that accepts an input of 18 V to 36 V and provides a 3.3-V output at 1 A, a 5-V output at 1.5 A, a 12-V output at 200 mA, and a — 5-V output at 250 mA. The converter features a 2-to-1 input voltage range, input-to-output isolation, soft start, an input Pi filter, short circuit protection, 380kHz switching frequency, flyback topology and four low-dropout linear regulators to minimize output noise. Furthermore, the converter can be synchronized to a system clock greater than 390 kHz and a TTL pulse width of 15 nS to 150 nS.
The converter comes packaged in a 2.0 × 2.0 × 0.395-inch coated metal case that provides six-sided EMI shielding. The standard operating temperature range is -25 °C to +60 °C. Other input and output voltage combinations are available upon request. Input voltage ranges of 2-to-1, 3-to-1, and 4-to-1 and output voltages from 1.8 V to 18 V with a combined total output power of 15 watts are available. Pricing for the BD16000 starts at $87.70 each.
Beta Dyne, Inc.
Windowed Watchdog IC
EM Microelectronic, an electronic systems company of the Swatch Group, introduces the EM6151, a highly integrated microprocessor voltage supervisory IC with programmable reset threshold voltages and a watchdog timer with programmable time-window and system-enable output. For maximum flexibility, this circuit is available in several versions, allowing for different ratios of the opened/closed window of the watchdog and power-saving function compatible with CAN-bus sleep mode. A low-power product, EM6151 draws only 35-uA quiescent current. Watchdog functions are used to ensure that system microprocessors or controllers do not operate erroneously as a result of the power supply voltage being out of specified operating range, which is especially critical during system power-up and power-down sequencing. The EM6151 features a time-windowed watchdog function that recognizes far more faults than the standard watchdogs used with microprocessors. Standard watchdogs, whether internal to the CPU or external, are dependent on the CPU hardware and software to generate a counter-reset signal and therefore will not reliably prevent hardware and software errors. In contrast, the EM6151 windowed watchdog ensures that the timer clear signal occurs within the correct time window (“opened” window); otherwise it activates a system reset or other error handling. This is the most robust and reliable type of watchdog action, because it effectively covers hardware errors as well as software errors such as code executing too slowly or too quickly. Indeed, code execution may be too quick when a slave MCU conflicts with its master or when the crystal oscillator malfunctions. Such errors and malfunctions are caught by a windowed watchdog but not by a standard watchdog, thus offering increased security.
In the EM6151, timings of the watchdog function are programmable using one external resistor to set the power-on reset delay and the watchdog time. The ratio for the close/open watchdog window is factory programmable. In addition, the reset-threshold voltage is also programmable using an external two-resistor voltage divider. Version 53 (V53) comes with a large opened watchdog window (67%), making it easier for the software programmer to issue a pulse to service the watchdog. Version 50 (V50) has a smaller opened watchdog window (33%), offering increased security in the application. Version 55 (V55) offers a Controller Area Network bus (CAN-bus) sleep-mode detector. In a typical automotive or industrial application, a central processor can issue a general “sleep” instruction to all EM6151V55-equipped peripheral modules. In sleep mode, the EM6151V55 will greatly reduce the rate that they generate reset signals. This greatly reduces power drain when the system is off and extends battery life, which is a tremendous benefit for vehicles and equipment that is garaged or off-line for periods of days or weeks at a time. The EM6151 windowed watchdog IC is available in a compact 8-pin SO8 package. Contact EM Microelectronic for pricing information.
Colorado Springs, Colo.
Tyco Electronics has introduced the next member of its Raychem FlexLite commercial wire family, FlexLite MT wire. FlexLite MT hookup wire, available in a range of 10-28 (AWG) complements previous offerings featuring a tough thin-wall insulation. With an average wall thickness of 6 mils (0.15mm), FlexLite MT wire (UL style 10916) has a UL rated operating temperature of up to 150 °C, and is suitable for general purpose use, including appliance, electronics, and electrical equipment that require a 600V rating. As today's applications become increasingly more compact and portable, FlexLite MT wire is designed to provide a lightweight solution, as well as excellent mechanical and chemical resistance by using a modified fluoropolymer insulation. This insulation also makes the wire easy to handle and compatible with automated stripping and terminating equipment.
In order to better meet consumer specifications, in addition to the standard tin plated copper conductor construction, FlexLite MT commercial wire can be made with other conductors upon request and it is available in all colors.
VOLTAGE DATA LOGGERS
Sentinel Voltage Data Loggers from AEMC Instruments are a new line of loggers that record True RMS measurements of AC voltage parameters. The voltage loggers provide isolated differential three-phase inputs and measure up to 600V. Voltage loggers are equipped with the Extended Recording Mode, which allows the operator to record over a long period of time by reducing the stored sample resolution of the oldest data and maintaining matching resolution for the newest data. This process continues until the recording is manually stopped. The loggers are able to store up to 480,000 points (1 MB) and 64 samples per cycle. Other storage modes include FIFO (First In, First Out) and Stop When Full. The voltage loggers are supplied with voltage leads and clips. Also included is DataView software for data storage, analysis and report generation. Unit pricing starts at $695.00.
SOTA ANNOUNCES A NEW SIZE 0203 CHIP RESISTOR
State of the Art (SOTA), Inc., a manufacturer of MIL-PRF-55342, space level and other high reliability chip resistors, announces the availability of a new 0203 (.020" × .030") size chip resistor on alumina. The new configuration provides a doubling of the voltage rating, from 15 V to 30 V on the same footprint, as compared to SOTA's 0302 chip. The power handling capability is comparable at 40 mW. The resistors are offered with gold, topside terminations for wire bonding, are MIL-PRF-38534 compliant, and provide excellent high frequency performance. Customers may choose from a wide variety of hi-rel screening options, including burn-in, offered by SOTA, or provide their own testing specification. Pricing for the new “0203” Series resistors starts at under $1.00 each in production quantities.
State of the Art Inc.
State College, Pa.