Hi all! We have a board which will occasionally see current spikes when it is used to power-up another device. The design of the traces for the steady state current is reasonably straight forward, so I'm comfortable with that aspect However, I'm not sure how to be certain the traces can handle the short duration (few milliseconds) current surges the system will see. My "gut feeling" is that such a short duration spike shouldn't be an issue. I'd like to find some information to collaborate that feeling though. I'm also wondering if there are any long term concerns about degradation of the trace. Over the course of the PCB's lifetime, it will be used to power up the system many times and thus be repeatedly exposed to these brief surges. (Not sure how many of these cycles it will see) Does anyone know of any resources I can use to calculate if the traces need additional width because of the spikes? We're already pretty much at the limit for what will fit on the board just with the steady state high current requirements. Any information about how many surges it could see before reliability would begin to be a concern? I think that covers the situation, but let me know if you need more info and thanks in advance for any help. Oh, this is a high-rel product and there are no fuses to consider in this scenario. Thanks, Bill --------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------