Power Electronics

Data Points

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External Power Supply Market to Approach $8 Billion in 2010

In a recently published report, the Darnell Group projects that the worldwide market for external ac-dc power supplies will rise from $5.023 billion in 2005 to $7.656 billion in 2010, a compound annual growth rate of 8.8% (see the figure). According to Darnell, a marketing research firm based in Corona, Calif., the external ac-dc power supply market is more than five times larger than the embedded ac-dc power supply market in unit terms and more than 15 times larger than the dc-dc converter market. However, the marketing research firm cautions that this market is ultra competitive and highly commoditized.

Darnell's report, “External AC-DC Power Supplies: Global Market Forecasts and Competitive Environment, Second Edition,” provides a detailed and in-depth examination of the external ac-dc power supply market and the trends that drive this market. One trend concerns low-priced, low-wattage external power supplies, which are said to be leading growth opportunities in Asia. Another market tendency is the replacement of desktop PCs with laptops in North America. According to Darnell, this trend is pushing notebook computers above the 100-W threshold. For more information, see www.darnell.com.

Start-up Develops PFC Controllers and Modules

Green Power Technologies (GPT), a start-up company based in Rehovot, Israel, continues to develop IC and modular products based on its power-factor correction (PFC) technology. Currently, GPT is finalizing the development of a digital power-management module prototype that promises to leapfrog existing ac-dc control solutions.

GPT's CEO, Eitan Cohen, believes that the digital product should be commercially available within 9 to 12 months. Described as a “digital power-management solution,” the new product will provide all of the features required in an ac-dc front end. GPT is currently considering the best market approach and is in discussions with two industry leaders for potential partnership agreements.

The company currently offers three PFC products. Released earlier this year, the GPTC Series Controller (part number GPTC110X) controls an active PFC stage operating under continuous-conduction mode (CCM) conditions. The chip provides near-unity power factor for universal line input but does not require sensing of the input voltage. GPT's control algorithm guarantees stable and error-free operation over the whole operational range without compromising THD. Available in 8- and 14-pin SOICs and DIPs, the GPTC110X includes all the housekeeping functions normally required in modern power systems.

Following the controller introduction, the company released the PF Switch-Assembly Series based on its patented modular approach. The switch assembly combines the active PFC controller with a power MOSFET, housing both die in a 5-pin TO-220 package. Using this assembly, an active PFC front end can be quickly designed by adding just a few components.

The assembly provides a complete PFC stage for up to a 700-W power level. Its robust control circuitry and smart construction permits the placement of the input inductor and line diodes anywhere in the equipment's housing. The product frees the designer from dealing with control loops and compensation networks, while simplifying the pc board design. A PF Switch-Assembly-based system is able to startup under full-load conditions and maintain stable output voltage over a wide range of operating conditions.

The company also uses its control technique in the PF Switch-Module. With the addition of some external passives, the PF Switch-Module provides a complete PFC stage up to a 2-kW power level. For more information on GPT, see www.g-p-t.com.

High-Voltage Op Amps Drive Piezo Devices

The spread of low-cost piezoelectric devices has created requirements for inexpensive driver amplifiers with high-voltage ratings and fast slew rates. To meet these needs, Apex Microtechnology has developed three high-speed, high-voltage op amps — the PA78, PA86 and PA69 — that also feature low quiescent current. In quantities of 10,000, unit pricing for these amplifiers ranges from $10.50 to $24.85.

Packaging for these op amps is in power SOPs and SIPs, making them a more compact and integrated alternative to existing piezo driver solutions. According to Apex Microtechnology, the new op amps will compete against discrete designs as well as against the company's hybrid products.

As an example of op-amp performance, consider the PA78, which is rated for single-supply operation up to 350 V. Housed in a 12-pin SIP, this amplifier also features a 150-mA (200-mA peak) output-current rating and a slew rate of greater than 350 V/µs, yet limits quiescent current (IQ) to 1 mA. To achieve that low current consumption in combination with high-speed and high-voltage capabilities, the amplifier employs dynamic current sources rather than the fixed current sources found in conventional op-amp designs. As a result, IQ in the PA78 varies as a function of the input signal.

These op amps target a growing number of piezo drive applications, which are found wherever ink-jet printing is used (see the figure). These applications require high voltage and high speed, because the faster the driver amplifier performs, the faster the ink-jet printer will produce its tiny droplets of ink. In addition, piezo transducers perform the positioning of wafers in photolithography equipment and appear in ultrasonic surgical tools and ultrasonic cleaning systems. For more details, visit www.apexmicrotech.com.

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