[SI-LIST] Re: anti-resonance point when use Embedded Capacitance Material
- From: "Grasso, Charles" <Charles.Grasso@xxxxxxxxxxxx>
- To: "istvan.novak@xxxxxxxxxxx" <istvan.novak@xxxxxxxxxxx>, Ken Wyatt <ken@xxxxxxxxxxxxxxxx>
- Date: Thu, 9 May 2013 21:22:52 +0000
Hello Ken,
When faced with large areas of pwb that have little or no components, it used
common practice for EMI guys to add lossy caps (the lossier the better)
to the planes in a regular pattern to minimize the effects of plane resonance.
With modern simulation tools, the resonant modes of the planes
can be simulated and caps added (in just the right spot!) to reduce the effect.
Chas
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On
Behalf Of Istvan Novak
Sent: Thursday, May 09, 2013 7:23 AM
To: Ken Wyatt
Cc: bruce@xxxxxxxxxx; si-list@xxxxxxxxxxxxx
Subject: [SI-LIST] Re: anti-resonance point when use Embedded Capacitance
Material
Ken,
Bypass capacitors with more lossy dielectrics do help somewhat, but the
dielectric loss shows up strongly in the ESR only at frequencies much lower
than the series resonance frequency, where we usually dont need the higher ESR.
Very lossy (and sloppy) dielectrics, such as Z5U and Y5V are good for cheap
consumer electronics, but for professional circuits there are many drawbacks
and it is not the best thing to use them. Ceramic capacitors with user-defined
ESR are available from two of the major capacitor vendors, so they can be used
when we need the highest performance and can afford the higher cost for these
parts.
Regards,
Istvan Novak
Oracle
On 5/9/2013 9:00 AM, Ken Wyatt wrote:
> Hi Group & Bruce,
>
> I'm kind of a "newby" when it comes to SI, but am reading Lee Richey's
> books on the subject.
>
> One thing he recommends for PDN designs is the use of bypass
> capacitors with a more lossy dielectric (higher ESR), such as X5R, Z5U
> or Y5V, to dampen the anti-resonance. Would this be a reasonable thing
> to try?
>
> Ken
> ___________________
> Kenneth Wyatt
> Wyatt Technical Services LLC
> Woodland Park, CO
> ken@xxxxxxxxxxxxxxxx <mailto:ken@xxxxxxxxxxxxxxxx> Web
> <http://www.emc-seminars.com> Newsletter
> <http://emc-seminars.us1.list-manage.com/subscribe?u=987f203d1f64dd89f
> 06b0c3f5&id=a00f29a904> Connect with me on LinkedIn
> <http://www.linkedin.com/in/kennethwyatt>!
>
> On May 9, 2013, at 5:16 AM, Istvan Novak wrote:
>
>> Hi Bruce,
>>
>> The anti-resonance between the static capacitance of planes and
>> inductance of bypass capacitors will always be present unless you
>> either match the plane impedance with the ESRs of capacitors or
>> overwhelm the antiresonance with MANY low-inductance bypass
>> capacitors. The antiresonance is present with any laminate material, thin
>> or thick.
>> When you use thin laminates (Embedded Capacitance Material), the
>> resonance magnitude and frequency both get lower with respect to a
>> thicker laminate. First you have to determine whether the resonance
>> causes a problem for power, signal integrity and EMI. If you dont
>> excite the resonance, you dont need to care.
>>
>> Regards,
>>
>> Istvan Novak
>> Oracle
>>
>>
>>
>>
>> On 5/9/2013 2:26 AM, Bruce wrote:
>>> Hi Expert
>>>
>>>
>>> We use Embedded Capacitance Material for better PDN and less
>>> capacitor component. According to PDN Simulation. We notice that is
>>> an anti-resonance point between capacitor and Plane.
>>>
>>>
>>>
>>> We can find that when use Embedded Capacitance Material. There are
>>> much better in most frequency but near anti-resonance point.
>>>
>>>
>>>
>>> In this case. We have to solution.
>>>
>>> 1. Try to reduce the anti-resonance point. We need many high
>>> frequency
>>> capacitor component. That is not good because we want to reduce the
>>> number of capacitor component. Our purpose is reduce 70% number of
>>> capacitor component.
>>>
>>> 2. Keep this anti-resonance point. That maybe have a risk if
>>> there is
>>> some noise by chance in this frequency
>>>
>>>
>>>
>>> How about your suggestion? Please let me know if my question is not
>>> clear enough.
>>>
>>> Thanks
>>>
>>>
>>>
>>> Best Regards,
>>>
>>> Bruce Wu
>>>
>>>
>>>
>>>
>>
>>
>> ------------------------------------------------------------------
>> To unsubscribe from si-list:
>> si-list-request@xxxxxxxxxxxxx <mailto: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 forum is accessible at:
>> http://tech.groups.yahoo.com/group/si-list
>>
>> 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
>>
>>
>
------------------------------------------------------------------
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 forum is accessible at:
http://tech.groups.yahoo.com/group/si-list
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
------------------------------------------------------------------
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 forum is accessible at:
http://tech.groups.yahoo.com/group/si-list
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:
