The terminology of "series" or "parallel" resonance when speaking of quartz crystal resonators refers to the resonance mode where calibration was established. Physically there is no difference between a series and parallel resonant crystal. The type of resonance utilized in the oscillator has to do with the oscillator topology. Some oscillators require the crystal to exhibit a low impedance at resonance (the series mode), whereas other oscillator types require a high impedance (parallel mode) to sustain oscillation. Using a "parallel" resonant crystal in a "series" resonant oscillator will result in a slightly different frequency of oscillation than the crystal vendor intended, but it shouldn't materially affect the oscillator functionality. -Ray Anderson Xilinx Inc. > -----Original Message----- > From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] > On Behalf Of Richard Jungert > Sent: Monday, February 01, 2010 1:49 PM > To: steve weir; tlx6f@xxxxxxx; chundis@xxxxxxxxx; si list freelist > Subject: [SI-LIST] Re: follow up: Re: Query about Oscillator problem > > Guys > > It may very well be that the series resonant quartz won't work and that > you may need to get a parallel resonant XTAL. Series resonant can get you > into trouble. I would go with the crystal type/mfg that Motorola > recommends. > > I would bet dollars to doughnuts that the resonant type is the issue here. > > Richard Jungert > > > > > > > Date: Sun, 31 Jan 2010 15:20:46 -0800 > > From: weirsi@xxxxxxxxxx > > To: tlx6f@xxxxxxx > > CC: chundis@xxxxxxxxx; si-list@xxxxxxxxxxxxx > > Subject: [SI-LIST] Re: follow up: Re: Query about Oscillator problem > > > > Li, that is not correct. NPO capacitors are high stability and high Q. > > They are great for the crystal tuning caps where both characteristics > > are a plus. But the high Q can actually create unwanted resonance > > problems in the PLL power filter. > > > > Steve. > > Li, Tianqi . (S&T-Student) wrote: > > > Sree, > > > > > > I forget sth. You need to check the PLL filtering capacitors of > MCF5212. > > > In most cases CPU will leave out 2 or 3 power pins for filtering PLL > > > noise. Capacitors on these pins should also use NPO for a better > > > performance. > > > > > > And you also need to find at what value of Vpp of XTAL droped to the > PLL > > > start to lose locking. If the value is out of MCF5212 spec, the root > > > cause is surely on XTAL tank circuit; If not, it might be XTAL's > glitch > > > aroused. You can use scope to test the eye diagram and find the > glitch. > > > > > > Tianqi Li > > > This email and any attachments are intended for the sole use of the named recipient(s) and contain(s) confidential information that may be proprietary, privileged or copyrighted under applicable law. If you are not the intended recipient, do not read, copy, or forward this email message or any attachments. Delete this email message and any attachments immediately. ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List technical documents are available at: http://www.si-list.net List archives are viewable at: //www.freelists.org/archives/si-list Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu