In my experience, I have always used the highest clock generated within the device!! i.e. if a 66MHz (external) clock is taken in to a processor and a PLL then multiplies up by 8 the highest fundamental is 528MHz. The PLL circuitry is generating a free running clock [with fast rise/fall edges] albeit within the processor and the higher clock (and harmonics thereof) can couple on to the other IO entering/exiting the processor. The possibility of the processor itself being resonant at the higher harmonics also increases.
____________________________________ Andy White, Senior EMC Engineer, Ericsson Wireless Communications Inc. San Diego, CA 92121 Tel 858 332 6214 / 877 877 7799 ext 26214 Fax 858 332 7311 e-mail andy.wh...@ericsson.com ____________________________________ -----Original Message----- From: John Harrington [mailto:jharring...@ktlcanada.com] Sent: 02 August 2001 12:42 To: Gary McInturff Cc: emc-p...@majordomo.ieee.org Subject: Re: FCC - radiated emission up to 10th harmonic Gary, Amund We have always chosen the highest "fundamental" frequency as the highest original frequency generated, normally a crystal or other oscillator. Frequencies derived from the fundamental, via multipliers etc, are not considered as fundamental. John Harrington RF Group Manager Nemko Canada -----Original Message----- From: Gary McInturff <gary.mcintu...@worldwidepackets.com> To: 'am...@westin.org' <am...@westin.org>; emc-p...@majordomo.ieee.org <emc-p...@majordomo.ieee.org> List-Post: emc-pstc@listserv.ieee.org Date: Thursday, August 02, 2001 11:59 AM Subject: RE: FCC - radiated emission up to 10th harmonic > > Interesting question and there is a corollary to it. If a crystal >oscillator is stepped up in frequency, with PLL circuitry for example, now >what is the highest frequency. > My current opinion is that for Amund's question it is the crystal >frequency, and to mine, it is the PLL frequency. IN both cases they >represent the highest repetitive clock speed or digitally generated >frequency. > Interested in seeing the other responses. > Gary > >-----Original Message----- >From: am...@westin.org [mailto:am...@westin.org] >Sent: Wednesday, August 01, 2001 1:19 PM >To: emc-p...@majordomo.ieee.org >Subject: FCC - radiated emission up to 10th harmonic > > > >Dear members, > >FCC 2.1057 is about radiated emission. They say :"If the equipment operates >below 10GHz: to the tenth harmonic of the highest fundamental frequency or >to 40 >GHz, whichever is lower". > >I ask: Highest fundamental frequency, is it the crystall oscillator with >highest frequency or is it the highest operating frequency within the EUT >(after mixing, muliplier, etc..) ? > >Best regards >Amund Westin >Oslo, Norway > >-- >Get your firstname@lastname email for FREE at http://Nameplanet.com/?su > >------------------------------------------- >This message is from the IEEE EMC Society Product Safety >Technical Committee emc-pstc discussion list. > >Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > >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: > Michael Garretson: pstc_ad...@garretson.org > Dave Heald davehe...@mediaone.net > >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.rcic.com/ click on "Virtual Conference Hall," > >------------------------------------------- >This message is from the IEEE EMC Society Product Safety >Technical Committee emc-pstc discussion list. > >Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > >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: > Michael Garretson: pstc_ad...@garretson.org > Dave Heald davehe...@mediaone.net > >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.rcic.com/ click on "Virtual Conference Hall," > > ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Michael Garretson: pstc_ad...@garretson.org Dave Heald davehe...@mediaone.net 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.rcic.com/ click on "Virtual Conference Hall,"
