[SI-LIST] Re: follow up: Re: Query about Oscillator problem
- From: Richard Jungert <r_jungert@xxxxxxxxxxx>
- To: ray anderson <ray.anderson@xxxxxxxxxx>, steve weir <weirsi@xxxxxxxxxx>, <tlx6f@xxxxxxx>, <chundis@xxxxxxxxx>, si list freelist <si-list@xxxxxxxxxxxxx>
- Date: Mon, 1 Feb 2010 14:49:49 -0800
Here is a great app note on how to specify a crystal.
http://www.maxim-ic.com/app-notes/index.mvp/id/726
According to Intel app note I just looked at the series resonant ones are more
sensitive to temp variation than parallel types.
Richard
> Subject: RE: [SI-LIST] Re: follow up: Re: Query about Oscillator problem
> Date: Mon, 1 Feb 2010 14:19:47 -0800
> From: ray.anderson@xxxxxxxxxx
> To: r_jungert@xxxxxxxxxxx; weirsi@xxxxxxxxxx; tlx6f@xxxxxxx;
> chundis@xxxxxxxxx; si-list@xxxxxxxxxxxxx
> CC: raya@xxxxxxxxxx
>
> 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.
>
>
_________________________________________________________________
Hotmail: Free, trusted and rich email service.
http://clk.atdmt.com/GBL/go/201469228/direct/01/
------------------------------------------------------------------
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
Other related posts:
