Oh, the things you can learn trolling the aisles at tradeshows and talking to engineers! There was lots to check out last month at Power Systems World in Detroit.

Tabtronics CTO Victor Quinn presented a seminar about evaluating transformer dissipation and energy storage in switch-mode power supplies to evaluate transformer designs winding-layer by winding-layer. He developed a rigorous comparison of solenoidal and planar transformer performance and looked at several versions of planar conductor configurations, including pc-board, flex-circuit, and annular-wound magnet wire for offline applications. You can request copies of the presentation at www.tabtronics.com.

At International Rectifier's booth, Carl Blake told me about the link in power supplies between upstream heat and downstream performance. He said cutting the heat the ac-dc rectifiers dump into the circuit board improves downstream dc-dc converter rectifier efficiency. You can do that if upstream rectifiers are in IR's DirectFET surface-mount (SMT) package—which has a metal lid bonded to the drain—instead of SO-8s. Of course, you need air flow.

Blake showed me several prototype supplies using the new 40- and 100-V DirectFETs. IR had measured temperatures and efficiencies with 400-LFM flows and found primary-side package temperatures around 40°C cooler than equivalent SO-8s and secondary-side package temperatures around 15°C cooler. Overall, efficiency was up better than a percent in that low-nineties range where further gains in efficiency are so hard to come by.

Click here to download the PDF version of this entire article.

Reprints

Printer-Friendly

Email this Article

RSS

Submit PlanetEE del.icio.us Digg Reddit Newsvine StumbleUpon Netscape Yahoo MyWeb Live Bookmarks Fark  Submit

Font Size

What's This?

MLCCs Stand Up To ESD Quad-Output Controller Trims Parts Count Video Filter/Buffers Boost Performance And Integration 45W Supplies Power Electrostatic Air And Oil Cleaner Devices Desktop HDD Packs 500 GB Per Disk 1A Switching Regulators Perform As High-Efficiency Replacements

A New Design Inflection Point Forecasting Industry Growth For 2009 And Beyond EDA Retools To Exploit Multicore Architectures Design And Verification Move Up In Abstraction EDA Retools To Exploit Multicore Architectures A New Design Inflection Point Design And Verification Move Up In Abstraction Challenges Lurk For 22-nm Physical Implementation

1) Build A Smart Battery Charger Using A Single-Transistor Circuit (243 views today) 2) 2008 BEST Electronic Design Winners (108 views today) 3) What's All This Transimpedance Amplifier Stuff, Anyhow? (Part 1) (93 views today) 4) Efficient DC-To-AC Inverters Charge Equipment Racks (82 views today) 5) 1-A Switching Regulators Operate With 96% Efficiency To Replace Linear Regulators (81 views today) ALL TOP 20

POST YOUR COMMENTS HERE Name: Email:
Your Comments: Enter the text from the image below Please refresh the page if you have trouble reading this text.