At 11:50 AM -0700 4/13/04, Fred Townsend wrote: >John Woodgate wrote: > >>I read in !emc-pstc that Chris Maxwell >><mailto:chris.maxw...@nettest.com><chris.maxw...@nettest.com> wrote >>(in >><mailto:39F7060A00B5E946B516261C07744 c002a...@utexch1w.gnnettest.com><39F706 a00b5e946b516261c077441c002a...@utexch1w.gnnettest.com>) >>about 'laminated capacitor source' on Tue, 13 Apr 2004: >> >>>I think that they gave the product a name something like >>>the "Micro Q" series. >>> >> >>A definite marketroid name. Do we want our decoupling capacitors to have >>extremely low Q? >> >Yes, John, you want the bypass circuitry to be low Q! [...] > >Fred Townsend
And another GOTCHA if I may. Lossy caps (or anything lossy in this business) will dissipate some heat. If your power rail has high di/dt or RF currents, the cap will heat up. The cap life may shorten insignificantly, or given the severe conditions end quickly and spectacularly. Lossy caps may bring down your predicted MTBF, but depending on other failure contributors (such as stressed tantalum caps) it is probably a very acceptable trade to reduce emissions. Eric Lifsey http://www.relia.net/~elifsey/ This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ieee-pses.org/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
