ROHM is announcing the availability of a 12- to 76-Vdc input, 3A variable output voltage, dc-dc buck converter with integrated 76V MOSFET optimized for high power (high voltage x large current) applications such as motors, factory automation equipment, communications infrastructure, and industrial machinery. The BD9G341AEFJ utilizes ROHM's high-voltage 0.6um BiCDMOS process to achieve a maximum breakdown voltage of 80V (the highest in ROHM's non-isolated dc-dc converter lineup) and a continuous operating input range of 12- to 76-Vdc, while market-proven advanced analog design technology claims the highest conversion efficiency in its class.

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In addition, multiple protection circuits minimize heat generation, even during output pin shorts (contact), preventing possible damage and increasing reliability compared with conventional products. And the compact 8-pin package requires fewer parts and reduces mounting area, contributing to easier PCB placement and end-product miniaturization.

High power conversion efficiency in the 76V dc-dc converter class has been achieved by leveraging advanced market-proven analog design technology. Efficiency is increased by 1.5% compared to conventional products during stable operation and by as much as 19% (300kHz oscillation frequency, 48V supply/5V output), improving energy savings in industrial equipment.

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Unlike conventional protection functions that normally cannot suppress heat generation during output shorts (contact), ROHM's proprietary protection function minimizes heat generation during accidental output shorts, preventing damage and improving system reliability. The BD9G341AEFJ is offered in a compact 8-pin package (4.9mm x 6.0mm, t=1.0mm) and features a highly integrated design that reduces the number of parts required from 17 to 12, simplifying end-product design, bill of materials costs, and development efforts.

Applications are expected to include: Communication infrastructure such as switching and base stations, office telephone systems, routers, and other equipment requiring 48V input. Motor devices exposed to high surge voltages (e.g. electric bicycles, vacuum cleaners, industrial controllers). The BD9G341AEFJ is available immediately and costs $1.82 in lots of 2,500 pieces.

source: http://www.powerpulse.net/story.php?storyID=33299

Linear Technology Corporationannounces the LTC3884, a dual-output current-mode synchronous step-down dc-dc controller with programmable loop compensation and I²C-based PMBus interface. This device enables the use of very low dc resistance (DCR) power inductors (0.3 milliohms) by enhancing the signal-to-noise ratio of the current sense signal to maximize converter efficiency and increase power density.

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The LTC3884 operates over an input voltage range of 4.5V to 38V and produces output voltages up to 5.5V. Up to 6 phases can be paralleled and clocked out-of-phase to minimize input and output filtering. When both outputs are paralleled, the LTC3884 provides less than ±5% current mismatch between phases. Alternatively, the LTC3884 can be used with the LTC3874 phase extender, making it ideal for high current requirements up to 240A. Onboard differential amplifiers provide true remote output voltage sensing of both outputs. Applications include power distribution, redundant (n+1) supplies, FPGA, ASIC and processor power.

The LTC3884 has a selectable fixed operating frequency from 200kHz to 1MHz or it can be synchronized to an external clock. Powerful 1.1Ω onboard all N-channel gate drivers minimize MOSFET switching losses. The LTC3884’s adjustable and precise current limit threshold can be configured for very low sense voltages from 10mV to 30mV, further reducing power loss. Additional features include input current sensing, two power good output signals, programmable soft-start and programmable fault recovery method.

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The LTC3884 is supported by the LTpowerPlay™ software development tool with graphical user interface (GUI). Its serial I²C-based interface enables system designers and remote operators to command and supervise a system’s power condition and consumption. The capability to digitally change power supply parameters reduces time-to-market and down time, eliminating what would typically require physical hardware, circuit or system bill-of-material modifications. The LTC3884 simplifies system characterization, optimization and data mining during prototyping, deployment and field operation.

In addition to delivering power to a point-of-load, the LTC3884 features configurability and telemetry monitoring of power and power management parameters over PMBus - an open standard I²C-based digital serial interface protocol. The LTC3884’s 2-wire serial interface enables outputs to be margined, tuned and ramped up and down at programmable slew rates with sequenced delay times. Input and output voltages, along with input and output currents and temperature are readable. The device is comprised of fast analog control loops, precision mixed-signal circuitry and EEPROM, and is housed in a 7mm x 7mm QFN-48 package.

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To evaluate the performance of the LTC3884, the LTpowerPlay GUI is free for download. USB-to-PMBus converter and demo kits are also available. With ±0.5% maximum dc output error over temperature, ±1.5% current read back accuracy, integrated 16-bit Delta-Sigma ADC and EEPROM, the LTC3884 combines best-in-class analog switching regulator performance with precision mixed-signal data acquisition and nonvolatile fault logging. Channels can accurately share current in both steady state and transient conditions. At start-up, output voltages, switching frequency and channel phase angle assignments can be set by pin-strapping resistors or loaded from internal EEPROM. 1,000-piece price is $6.35 each.

source: http://www.powerpulse.net/story.php?storyID=33315

Artesyn Embedded Technologies today launched the ADQ500 series, new 500-Watt quarter-brick isolated dc-dc converters with the high efficiency and thermal performance demanded by telecom network and data center equipment. ADQ500 series converters are Artesyn's first to have both a digital interface version and an analog interface version, with both following the industry standard DOSA footprints. The digital interface version allows communication to the converter via the PMBus command protocol with control and monitoring functions for voltage, current, temperature and the setting and reporting of fault conditions. Standard analogue control features include output voltage trim, output voltage sense compensation and remote enable functions.

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The ADQ500 series has an input voltage range of 36- to 75-Vdc and is primarily designed for use with regulated 48-Vdc supplies in computing and server applications, as well as standard -48-Vdc supplies found in telecom equipment. Capable of delivering up to 50A output current with a single fully-regulated 12-Vdc output the converters have no minimum load requirement.

An ultra-high efficiency of typically 95.5 percent at full load and the ability to operate over an ambient temperature range of minus 40 to 85 degrees Celsius, makes them an ideal choice for the isolated converter in a distributed power architecture supplying power to non-isolated converters. Their open-frame design is optimized for forced air or conduction cooling and an aluminum baseplate option is available for enhanced thermal performance. The conversion technology employs 175 kHz fixed frequency switching to help minimize external EMI filtering requirements.

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The converters are protected against output overvoltage, output overcurrent and overtemperature conditions. ADQ500 series converters have an enhanced pre-bias start-up capability and for high current applications two converters can be connected in parallel, automatically using the droop method of current sharing.

Artesyn ADQ500 series converters are low profile units that are ideal for systems with demanding inter-board spacing requirements; the open-frame models have an installed height of 0.43 inch (11 mm), while the baseplate versions require 0.52 inch (13.3 mm).

source: http://www.powerpulse.net/story.php?storyID=33313

The HCS Series from Stackpole now includes an 0.2 milliOhm resistance value in the 3920 and 5930 chip sizes. This extremely low resistance value allows higher power current sensing with greater efficiency. In addition, the all-metal raised element means lower PCB temperatures due to increased convection under the part. The HCS typically runs 15 to 30 degrees C cooler than comparable sized flat chips.

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These low resistance SMD shunts also provide high accuracy with tolerances down to 1% and TCR as low as 50 ppm for select resistance values. The HCS Series is AEC-Q200 qualified and is designed for power supplies for a wide range of end products including HVAC, robotics, data and voice telecom, fuel power engine controls, electric motors, portable charging stations, and electric scooters.

Pricing for the HCS Series varies with size, resistance value, tolerance, and TCR. Contact Stackpole or a franchised distributor partners for specific pricing.
 
source: http://www.powerpulse.net/story.php?storyID=33310

Analog Devices, Inc. today introduced a 24-bit data acquisition system-on-chip (SoC) series designed to improve the performance of protection, monitoring, and power quality measurement equipment used to manage transmission and distribution (T&D) within smart grid systems. The AD7770 enables higher performance and smaller form factor protection relays, while the AD7771 enables power quality measurement equipment to provide early detection of power grid electrical faults. The third SoC in the series, the AD7779, ensures fast power-up in circuit breaker equipment.

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All three devices in the AD777x series claim the industry's best combination of dynamic range and data throughput and feature eight simultaneous sampling channels that measure the output from current and voltage sensors in three-phase power applications. Each SoC channel achieves 112-dB of dynamic range at 8 kSPS, enabling the consolidation of protection and measurement functions on a single A/D converter channel. The AD777x series also includes an integrated sample rate converter, which simplifies the design challenge associated with making the power quality equipment compliant with the IEC61000-4-30 Class A standard.

The AD777x series incorporates a programmable gain amplifier (PGA) to scale various sensor outputs, allowing system designers to use a common platform for applications with different accuracy requirements and input sensor types, including current transformers, potential transformers, and resistive strings.

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Additionally, the AD777x series lowers total system cost by eliminating the need for external components such as signal conditioning amplifiers and phase-locked loops (PLLs). The entire AD777x series incorporates sample rate converters that enable the fine adjustment of the sampling rate and maintain coherency to a 0.01Hz change in line frequency over a 50Hz (-15%) to 60Hz (+15%) range. This is a requirement for the IEC61000-4-30 Class A power quality standard.

The new devices also incorporate a number of on-chip diagnostic features that ease the design process for end-equipment safety integrity level (SIL) certification. An additional low-resolution SAR A/D converter channel operates from a separate power supply and provides data for system and chip diagnostics, improving confidence in data integrity and boosting overall system reliability.

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The AD7771’s high dynamic range, coupled with a high sampling rate, enables the reduction of the fast Fourier transform (FFT) noise floor. This enhances the detection of abnormal frequency spurs, which can signal a developing electrical fault, and enables early warning detection and preventative maintenance by power quality measurement equipment.

All three SoCs are packaged in 64-lead LFCSP and are sampling now, the AD7779 is scheduled for full production in January 2016 while the AD7770 and AD7771 are scheduled to enter production in May 2016. The AD7770 has an input bias of +/- 4 nA, an output data rate of 32kSPS, and a unit cost of $6.97 in lots of 1,000. The AD7771 has an input bias of +/- 4 nA, an output data rate of 128kSPS, and a unit cost of $7.94 in lots of 1,000. The AD7779 has an input bias of +/- 2nA, an output data rate of 16kSPS, and a unit cost of $5.90 in lots of 1,000.

source: http://www.powerpulse.net/story.php?storyID=33324