Powering Up For 2005

Paul Whytock looks at the latest technology taking us into the New Year.

Electronic manufacturers have got to get green. Environmental legislation and ecological pressures demand this, but it's a lot more palatable if the greening process also brings financial reward. This was the thinking behind Power Integrations' suite of solutions that are geared to comply cost-effectively with the recently unveiled mandatory energy-efficiency standards for California, USA.

Introduced by the California Energy Commission (CEC), the mandatory standards demand stringent energy efficiency requirements on AC-DC and AC-AC external power supplies. The standards apply to an array of electronic products employing external power supplies (chargers/adapters), including cell phones, cordless phones, portable music players and game systems, toys, tools and many more.

From July 1, 2006, external power supplies manufactured for retail sale in California must meet minimum efficiency standards in both active and no-load modes. This, says the company, practically rules out the use of linear transformers, which Power Integrations has dubbed the "energy vampires," in external power supplies.

Complete details on the new requirements, which are included in the newly updated California Appliance Efficiency Regulations, can be found on the CEC Web site at www.energy.ca.gov/appliances.

Power Integrations has available some IC solutions to assist manufacturers in meeting these standards. The company's EcoSmart technology enables switched-mode power supplies that consume less electricity and are supported by design tools that include application notes, data sheets, reference design kits and the company's power-supply design software, PI Expert.

The Californian requirements, which are said to be the first-ever mandatory standards specifically addressing external power supplies, reflect the widespread availability of cost-effective alternatives to older, inefficient power-supply technologies. California law demands that the CEC appliance efficiency standards be cost-effective based on a reasonable use pattern, meaning that they must not result in added total costs to the consumer over the life of the appliance.

"These new standards are an acknowledgement that proven, readily available technologies, such as EcoSmart integrated circuits, are a cost-effective way to make power supplies more efficient," explained Balu Balakrishnan, president and CEO of Power Integrations. "Our ICs enable manufacturers to meet all current and proposed energy standards worldwide, and are already being used to meet the requirements of Energy Star, the European Commission Code of Conduct, the U.S. One-Watt Executive Order, and many other regulations and standards around the world."

Ecos Consulting, an environmental consulting firm, estimates that there are at least 145 million external power supplies in service today in California, with an additional 28 million sold in the state annually. "Improving the efficiency of external power supplies offers a tremendous opportunity for energy savings," noted Chris Calwell of Ecos. "If all of the external power supplies currently in use in California were energy-efficient, California could be saving more than 360,000 tons of carbon-dioxide emissions annually, an amount equal to the annual emissions of more than 60,000 automobiles.

On a lighter but nevertheless a technically high note, International Rectifier has just unveiled its IRF6665 DirectFET MOSFET designed for medium power Class D audio amplifiers. With this device, the parameters are tuned specifically for improved audio performance such as efficiency, total harmonic distortion (THD) and power density. Applications for Class D amplifiers range from battery-powered portable products to high-end professional amplifiers, musical instruments and car and home multimedia systems.

In addition to application-tuned silicon, IR's DirectFET packaging technology enhances performance in Class D amplifier circuits by cutting lead inductance with the result that switching performance is boosted and EMI noise cut.

Thermal efficiency enables 100W operation into 8ohms without a heatsink. Eliminating heatsinks shrinks circuit size and bulk, which allows designers greater layout flexibility while cutting amplifier cost.

While on the subject of Class D, IR recently launched the IRAUDAMP1 Class D audio amplifier reference design for 500W + 500W peak stereo output Class D audio amplifiers. It features the 200V-rated IR2011S high-speed gate driver IC, which drives a pair of IRFB23N15D HEXFET MOSFETs for each channel in the power stage to provide the amplified audio PWM waveform.

The reference design is a complete analog input, Class D audio power amplifier with 500W + 500W peak stereo output into 4ohms. The IRAUDAMP1 is based on a self-oscillating PWM modulator. This reference design is intended to demonstrate how to use the IR2011S, implement protection circuit features and design an optimum PCB layout.

Still in the USA, discrete components company ON Semiconductor used the Power Electronics Technology Conference in Chicago to announce it has pushed the Schottky voltage barrier above 200V with the introduction of the first 250V silicon Schottky for plasma/LCD television, power supply, consumer and automotive applications. The company has also developed two 200V Schottky rectifiers in SMC packages.

ON Semiconductor says its new 200V and 250V Schottkys outperform ultra-fast rectifiers' reverse recovery time, forward voltage and softness. As such, the new high voltage Schottky devices simplify system design and offer a more cost-effective solution for the growing number of 200-250V applications.

"Since first extending the Schottky voltage boundary to 200V in the early 1990s, ON Semiconductor has remained the high voltage silicon Schottky leader," said Keith Nootbaar, ON Semiconductor director of the Power Discrete products.

Back in the UK at its headquarters in Cambridge, CSR, the provider of Bluetooth wireless technology, has been chosen by Innovi Technologies to Bluetooth-enable its third-generation headset, the BLUETREK-S2. Using the lower power features of CSR's BlueCore technology, Innovi claims to have increased talk time to 10 hours and standby time up to 500 hours. The BLUETREK-S2 is available now across 40 countries worldwide.

CSR's single-chip Bluetooth design is claimed to minimise external components and makes minimal contribution to the BLUETREK-S2's 14gram weight.

In addition to standard Bluetooth power-down modes such as 'sniff' and 'park', CSR's BlueCore supports a deep-sleep mode, allowing the radio to effectively shut down certain Bluetooth functions when not in use. Some slick power management in BlueCore also means shorter wake up times. As a result, users experience no drop in performance despite the additional power saving measures.

"Our two primary aims were to ensure BLUETREK-S2's compatibility with a maximum number of handsets and to drive up the talk time and standby times of the headset," commented Phoebe Yi, sales and marketing director, Innovi. "With its power savings and its robust Bluetooth architecture, CSR's BlueCore solution allows the BLUETREK-S2 to be used with any Bluetooth-enabled mobile phone but also enables us to meet our power targets."

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Meanwhile, designer and manufacturer of mixed-signal semiconductors TDK Semiconductor launched a new member to its power-meter system-on-chip (SOC) product line. The TDK 71M6511 integrates a 21bit delta-sigma converter with three sensor channels, 32bit compute engine, MCU, RTC, LCD driver and precision voltage reference. It is ideal for tamper-resistant residential time-of-use (TOU) and Pre-payment metering.

Equipped with on-chip digital temperature compensation and TDK's patent-pending Single Converter Technology, the device delivers linearity over 2000:1 current range, and under adverse environmental conditions. Requiring a single 3.3V capacitive supply circuit, the 71M6511 consumes less than 9mA in mission and 4µA in battery backup modes, and it includes 64KB of FLASH, 7KB RAM, Real Time Clock (RTC), 5V LCD boost, 2+ UARTs, and an I2C interface.

Vishay Intertechnology has been busy announcing a couple of items. Firstly, the company has released details of itsVSMP1206 high-precision, surface-mount, Bulk Metal Z-foil resistor, which it says is the industry's first such device to combine a high power rating of 300 mW, load life stability of 0.01% and a low nominal TCR of ±0.5 ppm/°C in an industry-standard, surface-mount package.

Under varying ambient temperatures and current loads, the Bulk Metal Z-foil technology provides a high level of stability and dramatically reduces changes in resistance caused by current variation in power resistors and current-sensing resistors with low TCR and thermal resistance.

The technology also provides an inherently low and predictable ±0.5 ppm/°C TCR nominal. At its high power rating of 300 mW at 70 ppm/°C, the VSMP1206 has a low load life stability of ±0.01%, and an even lower ±0.005% load life stability at 200mW.

The VSMP1206 has a resistance range of 10W to 30kW and tight tolerance to ±0.01%.

The second item from Vishay Intertechnology is a new package type for its rectifier and transient voltage suppressor (TVS) products that delivers the same current and power ratings as the SMA package in a 44% smaller footprint. Setting a new standard for rectifier current density, devices in the new SMP package handle up to 2A while delivering industry-record levels of thermal resistance.

More than 45 new Vishay Semiconductors devices have been released in the new SMP package, including Schottky, standard, and ultra-fast rectifiers as well as TVSs.

The devices are aimed at power-supply and power-conversion applications in desktop and notebook PCs, servers, disk drives, mobile phones, PDAs, hybrid ICs, and automobile electronic sensors and control units, where the 1mm height and 2mm by 3.8mm footprint of the SMP package allows designers to reduce the size of power circuitry.

A dual, high-output-current, high-gain bandwidth operational amplifier has been launched by Texas Instruments from its Burr-Brown product line. Featuring low input voltage noise with low harmonic distortion, the OPA2614 provides high dynamic range for digital subscriber line (DSL) driver solutions in differential configurations. Typical applications include driving 16bit analog-to-digital converters, such as TI's ADS1605 16bit, 5MSPS ADC, high-capacitive loads and multiple load video lines. The OPA2614 is also well suited for precision baseband I/Q receiver channels, low-distortion audio amplifiers and active filters.

"The OPA2614 is an exceptional differential line driver through low to moderate frequencies. And the voltage feedback design gives the lowest total output noise for any currently available line driver solution," claimed Michael Steffes, strategic marketing manager of TI's high-speed signal processing group. The amplifier has a flexible supply range of 5V to 12V for single condition and ±2.5V to ±6V for dual design. Single +5V operation as a differential I/O interface to ADC inputs can support 14- to 16-bit converters with no degradation in SNR or SFDR.

The high power output stage of the OPA2614 can easily drive heavy filter loads. Very high output current (350mA) coupled with a low gain stable design provides a good solution for driving large capacitive loads through moderate frequencies.

A power circuit design simulation tool that enables its customers to conduct extensive simulations—in both the time and frequency domains—while maintaining complete control over every component and simulation criteria has been developed by Intersil. This edition of Intersil's iSim simulation tool, called iSim:PE, is free and runs on a standard PC to provide a design environment for validating application solutions based on Intersil's power management products.

iSim:PE has a schematic capture front-end and full-featured post analysis tools that includes equation-based analysis and plotting options. At the centre of each schematic is a validated model of the Intersil part providing an accurate simulation of the product's performance and features. Intersil has a library of iSim models and common components ready for download, and new ones in development. These enable users to create a back-annotated personalised design of the new schematic using existing components. iSim:PE is free at http://www.intersil.com/iSim.

In Eindhoven, Royal Philips Electronics continued its work of developing I2C solutions, introducing a new series of I2C-bus controlled push-pull general-purpose input/outputs (GPIOs). These devices offer reduced power consumption to extend the battery life of mobile devices. Philips is claiming an industry first in that the GPIOs feature both an interrupt output and reset input. This enables the I2C-bus to be quickly reset, which is important for hi-rel applications.

In applications such as mobile phones and PDAs, there is often a need for a greater number of GPIOs than that already integrated into the processor. Removing the internal pull-up resistor in existing Philips' GPIOs allows designers to add additional GPIOs into battery-powered systems while minimising the current consumption, thus sustaining battery life. Additionally, some of these new devices have both an interrupt output pin and hardware reset input pin. This provides server manufacturers such as IBM with an easy solution to recover the I2C-bus without the need to cycle power, enabling positive control of the bus and negating the need to restart the server when errors occur. The external reset pin offers the software programmers an easy way to simplify the programming sequence.

Power-One and C&D Technologies have agreed-in-principle to license Power-One's Z-One(dot) Digital Intermediate Bus Architecture (IBA) technology. C&D Technologies' Power Electronics Division will be authorised to incorporate the technology in its range of power-conversion products.

C&D intends to design, manufacture, and market Z-One Digital IBA Z-One compliant power systems, which include point-of-load (POL) converters that are virtually identical to Power-One's Z-Series. The companies feel that this alliance is a major step in accelerating adoption of the Z-One technology.

Steve Goldman, Power-One's chairman and CEO, says that"With the recent acquisitions of Datel and the former Power Systems Division of Celestica, C&D Technologies is now one of the major companies in the DC/DC power market. Its global customer base, leadership and vision are expected to help propel the Z-One power system into many different markets throughout the world, while allowing C&D to share in the benefits of the industry's first open-architecture power management solution."

Discussing the agreement, James D. Johnson, vice president and general manager of the C&D Technologies Power Electronics Division, said that C&D is pleased to join with Power-One and be part of the open source Z-One architecture. Power-system management is one of the most important functions in power design, and the Z-One power architecture provides significant advantages in this area. This technology is the only digitally integrated power system currently available and allows designers to achieve a new level of power-system integration. Johnson also feels that the Z-One power system addresses both power conversion and power management, with key features including up to a potential 90% reduction in design time, components and PCB traces.

Fairchild Semiconductor claims to have introduced the smallest footprint complementary MOSFET solution capable of delivering greater than 1A continuous current in miniature "spot" power and POL DC-DC switching converter designs. The FDC6020C integrates two MOSFETs into one ultra-small SuperSOT 6 FLMP (Flip-chip in a Leaded Molded Package); traditional solutions must use either two devices or a larger footprint package to offer similar high-performance specifications.

Products that benefit from the FDC6020C's thermal and efficiency characteristics include set-top boxes, digital still cameras and hard disk drives. The FDC6020C's low threshold gate (VGS = 2.5V) simplifies designs using 3.3V bus converters or single cell Li-Ion batteries. It does this by eliminating the need for charge pump circuits when higher gate drive voltages are not available. Additionally, each of the device's MOSFETs provide good RDS(on) characteristics (52 milliohms for the P-Channel and 27 milliohms for the N-Channel, at 4.5 V).

The FDC6020C's junction-to-case thermal resistance (1°C/W) and junction-to-ambient thermal resistance (68°C/W) facilitate the highest possible current densities while maintaining optimum operating temperatures.

"Many ultra-portable products are powered by a rechargeable single cell Li-Ion battery, rechargeable NiMH batteries, and alkaline cells. All of these power sources feature a continuously declining output voltage as the batteries are discharged during use. Consequently, the output voltage of these ICs, including the output drive voltages which control the MOSFETs in the circuit, will decrease as well," commented Mike Speed, Fairchild's communications marketing manager.

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The parent company of BI Technologies and Welwyn Components, TT electronics and distributors, Arrow, have concluded a new franchise distribution agreement under which Arrow will now handle the BI Technologies and Welwyn Components product portfolio throughout northern Europe.

TT electronics is an established supplier of electronic components to the world's leading manufacturers in the automotive, aerospace / defence, communications and industrial electronics sectors. As a result of the new agreement, Arrow will now stock and support the full range of BI Technologies and Welwyn Components passive components in Denmark, Finland, Norway, Sweden, the UK and Ireland, and the Baltic States.

Between them, the two TT electronics subsidiaries offer a variety of passive devices, including power, pulse, fusible, precision and other specialist resistors, trimming and precision potentiometers, R & RC networks, transformers and inductors.

Finally, a step-down (buck) regulator that draws an extremely low supply current has been developed by Micrel. The IC is for applications requiring low-noise DC-DC conversion such as 802.11 wireless cards, USB applications, cell phones, Mini Disk and MP3 players.

"The MIC2203 solves the noise versus light load efficiency dilemma experienced in many RF and audio applications," noted Tony O'Brien, Micrel's director for power products. "The MIC2203 is designed to remain in low noise PWM operation mode while the ultra-low 650uA supply current maintains high levels of efficiency at light loads."

The device is a high efficiency 1MHz pulse-width-modulated (PWM) synchronous buck converter, capable of >90 percent efficiency across a wide load range. A proprietary gate drive minimises switching losses; thereby allowing the new device to draw just 650µA of current while switching at 1MHz fixed operating frequency. The MIC2203 operates from 2.3V to 5.5V input voltages, with an output voltage adjustable down to 0.5V at 300mA.

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