I second Jack's thoughts on the wording from part 15, the wording "generated or used" is very clear. Furthermore, it seems obvious that a PLL generates a "new" fundamental frequency when multiplying its input frequency. This in turn, of course, creates a new set of harmonics and subharmonics related to the PLL's output frequency. Unfortunately, the FCC's rules do not make exceptions for generated signals which are only used internal to an IC. I know, anyone who's ever struggled with the emissions from a noisy PLL, like myself, has wished for such a break in the rules.
Regards, Don EMC Engineering InFocus Corp. > ---------- > From: Cook, Jack[SMTP:jack.c...@cax.usa.xerox.com] > Reply To: Cook, Jack > Sent: Thursday, August 02, 2001 10:27 PM > To: 'John Harrington'; Gary McInturff > Cc: emc-p...@majordomo.ieee.org > Subject: RE: FCC - radiated emission up to 10th harmonic > > > > So far, I haven't seen anyone quote the actual wording in FCC Part 15. > Here > it is, from the table in para. 15.33 (4). > > "Highest frequency generated or used in the device or > on which the device operates or tunes (MHz)" > > It doesn't appear to concern itself with *how* the signal is generated > (ocillator, PLL, etc.) or whether it's a fundamental or not. So, it seems > clear enough to me. Or maybe I'm missing something. > > Regards, > Jack > Xerox EMC > > > ------------------------------------------- > 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,"
