usually a boost regulator, depending on the stack of LEDs may go up to 12 to 18 volts
freq keep moving up, was around 1MHz now they're going around 8 to 10MHz, but very localized near the IC see Micrel's app notes - Robert - On Mon, 18 Dec 2006 09:36:56 -0600 Ken Javor <ken.ja...@emccompliance.com> wrote: > Forum Members, > > I am evaluating a PDA-like device for EMI/explosive > atmosphere usage. The > device has what appears to be an LCD type display, which > means it has > back-lighting. While the device runs off 4.2 Vdc > batteries, which are deemed > a safe potential, I expect that the back-light potential > is at a much higher > level, and that getting from 4.2 Vdc to that higher > potential can be > potentially noisy from an EMI point-of-view. > > Any commentary/experience to share? > > Thank you, > > Ken Javor - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________