[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
> >
> > -----Original Message-----
> > From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx]
> > On Behalf Of Li, Tianqi . (S&T-Student)
> > Sent: Sunday, January 31, 2010 4:44 PM
> > To: chundi srikanth; si-list@xxxxxxxxxxxxx
> > Subject: [SI-LIST] Re: Query about Oscillator problem
> >
> > Hi Sree,
> >
> > 1) I think you should check the tuning capacitors temp. grade first. In
> > this case you need to use NPO grade. If you are using Y5V, it won't work
> > well when temp. changes a lot.
> >
> > 2) Make sure that the tuning capacitor's value is same as what
> > recommended in MCF5212 app. Notes.
> >
> > 3) If capacitors are OK, you need to check XTAL power consumption and
> > make sure that MCF5212 can drive the XTAL at low temp.
> >
> >
> > Tianqi Li
> >
> > -----Original Message-----
> > From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx]
> > On Behalf Of chundi srikanth
> > Sent: Saturday, January 30, 2010 10:18 AM
> > To: si-list@xxxxxxxxxxxxx
> > Subject: [SI-LIST] Query about Oscillator problem
> >
> > Hi Friends,
> > I have designed a board with MCF5212 Processor and it was interfaced to
> > a
> > Pericom (saronix-ecera) NKS5 series quartz crystal. The crystals
> > operating
> > temperature was -40Deg c to 85Deg c. Earlier i tested this board and
> > everything was fine but now because the PLL was not locking and
> > processor
> > was working. So when i observed i noticed that at ambient temperature
> > the
> > crystal clock output was 2V p-p but with decrease in temperature the
> > clock
> > output was decreasing below 0.8V at -40 Deg c.
> >
> > Can you just give me an idea about this problem and what might be the
> > problem in this scenario?
> >
> > Thanks & Regards
> > Sree
> >
> >
> > ------------------------------------------------------------------
> > 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:
> > http://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:     
> >             http://www.freelists.org/archives/si-list
> >  
> > Old (prior to June 6, 2001) list archives are viewable at:
> >             http://www.qsl.net/wb6tpu
> >   
> >
> > ------------------------------------------------------------------
> > 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:
> > http://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:     
> >             http://www.freelists.org/archives/si-list
> >  
> > Old (prior to June 6, 2001) list archives are viewable at:
> >             http://www.qsl.net/wb6tpu
> >   
> >
> > ------------------------------------------------------------------
> > 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:
> > http://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:     
> >             http://www.freelists.org/archives/si-list
> >  
> > Old (prior to June 6, 2001) list archives are viewable at:
> >             http://www.qsl.net/wb6tpu
> >   
> >
> >
> >   
> 
> 
> -- 
> Steve Weir
> IPBLOX, LLC 
> 150 N. Center St. #211
> Reno, NV  89501 
> www.ipblox.com
> 
> (775) 299-4236 Business
> (866) 675-4630 Toll-free
> (707) 780-1951 Fax
> 
> 
> ------------------------------------------------------------------
> 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:
> http://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:     
>               http://www.freelists.org/archives/si-list
>  
> Old (prior to June 6, 2001) list archives are viewable at:
>               http://www.qsl.net/wb6tpu
>   
> 
                                          
_________________________________________________________________
Hotmail: Trusted email with Microsoft?s powerful SPAM protection.
http://clk.atdmt.com/GBL/go/201469226/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:
http://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:     
                http://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: