Passive Power Supply QA
1. Some claim that the stress-testing of products is like throwing them off the roof and claiming they are better for this experience. How does stress testing affect your tantalum cap longevity?(AVX) Actually, for many parts, the longevity is not the issue – it’s controlling the “infant mortality” so that more parts reach “steady-state” life. The preconditioning done (reflow, thermal cycle, surge) is an effective means of addressing this; for tantalum, a good reference that gives examples is the paper “Surge in Solid Tantalum Capacitors” by John Gill. 2. What’s the life (MTBF) of those capacitors under high temperature (85°C)?(AVX) The MTBF (Mean Time Between Failures) is the reciprocal of the Failure Rate in % / 1000 hrs. AVX commercial capacitors are monitored for actual failure rate at 85°C as standard, and different series will have different capabilities (1% / 1000 hrs is the standard reference for tantalum, while Oxicap Low ESR is 0.2% / 1000 hrs). MIL parts are 100% lot accepted at higher temperatures / acceleration and consequently meet lower failure rates at higher confidence levels than commercial parts. 3. Is tantalum capacitor use limited in some countries?(AVX) There are no specific limitations for tantalum compared to other capacitors, although all commodities manufactured in any given country will be subject to any export restrictions that country may have. 4. Where can I get detailed slides to learn about parameters/characteristics of the passive components for designs?(AVX) AVX posts many of these characteristics and pSpice software libraries on line at http://www.avxcorp.com/. We will be happy to provide any additional information you may need.
5. Why has India been completely left behind in power electronics? No passive component company other than Epcos has set up a production facility in India.(DENNIS) On India - In 2006, there were many small manufacturers of OPP film capacitors operating in India. In fact, this is the one dielectric where we see tremendous activity in both OPP film capacitors and metallized OPP film. The primary OPP film capacitors produced in India today are for power factor correction for power transmission and distribution, but also for magnetic ballast, microwave oven and many small motor run capacitor producers. Western vendors who have footprints in India have been mostly Philips (BCC now Vishay in Loni India) and the massive DC film capacitor production in Bangalore (Saha Kiel and others) for the local TV set market. Activity in 3Q 2006 for other dielectrics in India is extremely high, including tantalum. 6. What is the level of compliance with RoHS and Lead-Free?AVX maintains full RoHS compliance for the majority of commercial products as standard – and retains SnPb for all MIL & COTSplus series. RoHS info is available here. Alternate termination info is available here. (Panasonic) Most of our Passives are now RoHS compliant. Please find product RoHS information on the Panasonic Web site Here. 7. How does the FP series compare in price with the FK series?(Panasonic) Our FP Series, on a case size basis, is expected to be about 15 to 20% higher than the FK Series. |