<p>2. Reducing the antenna loop area by minimizing the enclosed loop area formed by the power line and its return path can reduce radiated emissions. Within printed circuit boards this area can be best reduced by placing the power line and return path one above the other on adjacent printed circuit board layers.</p>

Based on my earlier calculations, I was obviously expecting the Raspberry Pi to be slower than the ZedBoard. In fact, I was anticipating that it would be around three to four times slower overall when you consider the difference in DMIPS and the number of processors, but I wasn’t sure exactly what to expect. Once the Raspberry Pi was up and running, sure enough it was returning about 0.32KH/s, which is about a third of what the ZedBoard was achieving.

In June 1999, FSI launched Calypso and its integrated spin-on dielectric technology, based on the company's Polaris cluster tool platform, which serves photoresist-processing applications. Two years ago, FSI believed lower cost spin-on dielectric tools would beat CVD systems in depositing organic and inorganic thin films low-k rating below 2.7 (see June 23, 1999, story).

Last year, FSI also struck a development partnership with Dow Chemical Co. to apply Calypso and spin-on resin films for low-k dielectrics in 0.13-micron copper interconnects (see July 5, 2000, story). Mitchell said the partnership is still underway with Dow Chemical, which is promoting its organic polymer–called SiLK–for insulating layers in copper interconnects.


Power supplier Power-One Inc., Camarillo, Calif., reported that net sales for the first quarter ended April 1 increased $92.8 million, or 121%, to $169.9 million, compared with $77.0 million in the first quarter of 2000.

First-quarter results include $19.2 million in net sales from Powec AS, which was acquired on May 16, 2000.

Net income for the first quarter increased $17.9 million, or 22 cents per diluted share to $16.4 million, or 20 cents per diluted share, compared with a net loss of $1.5 million, or 2 cents per diluted share for the same period in 2000.


Excluding the acquisition-related charges, net income for the first quarter of 2000 would have been $8.6 million, or 11 cents per diluted share.

Cash earnings per share for the first quarter increased 85% to 24 cents per diluted share, compared to 13 cents per diluted share for the year-ago quarter.


Power-One reported a 180-day backlog at the end of the first quarter of $112 million, down 56% from the $255 million reported at the end of the fourth quarter 2000. The company's 90-day backlog also decreased to $92 million at the quarter's end, down 46% compared to the end of the fourth quarter 2000.

Net new orders were negative in the first quarter due to cancellations by several top customers. Additionally, many customers rescheduled previous orders from delivery in the second quarter to the end of the year and, to a smaller extent, into next year.

Shielding of the transformer can be beneficial as well. The idea is to put a shield between the high-voltage winding and the secondary circuits and to connect the shield to the return or high side of the primary circuits. This prevents common-mode currents from flowing into the secondary circuit and then into the chassis. After implementing a shield, we meet the emissions requirements achieving another 6 dB improvement.

To summarize, common-mode emissions are generated by a high-voltage waveform coupling through a capacitance, which eventually makes it to chassis and returns through the system’s input power connection. The obvious ways to reduce emissions are to reduce the amplitude of the switching voltage waveform, to divert the current with a shield or capacitor, and/or to add a series impedance. We applied the first two techniques in the paper to demonstrate we can build a low-power, AC input adapter to meet EMI emissions without a common-mode inductor.

I would like to thank GCi Technologies in support of this project with their numerous transformer iterations that allowed us to pass emission requirements. Please join us for the next Power Tip where we will look at synchronous rectifiers in discontinuous flybacks. See the index of all Power Tips articles (Word .doc file).

Check out TI PowerLab Notes for a designer’s perspective on his power supply designs. For more information about this and other power solutions, visit: www.ti.com/power-ca.

SINGAPORE — Japan's Toshiba Corp. and Matsushita Electric Industrial Co. Ltd. today announced plans to start construction on the world's largest manufacturing plant for thin-film transistor LCD panels here next month after the two companies begin the operation of a new Singapore joint venture on May 1.

Skokie, ILL. – Ohmite Manufacturing Co. is offering 1 percent, as well as 5 percent, tolerance in its LVC series current-sense resistor family. The resistors, made with thick film on an alumina substrate, are available in 1206 and 2512 packages and are rated at 0.5 and 1 watt, respectively, at 70 degrees C. Resistance values range from 0.010 to 1 ohm.

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