[SI-LIST] Re: Self Impedance Analysis of Power Distribution Network
- From: Muhamed Semic <Muhamed.Semic@xxxxxxxxxx>
- To: "balaseven@xxxxxxxxx" <balaseven@xxxxxxxxx>, "weirsi@xxxxxxxxxx" <weirsi@xxxxxxxxxx>
- Date: Mon, 26 Nov 2012 10:21:21 +0000
It is not device frequencies (clock frequency) that you should base your
calculation, you should use the rise time of device (BW = 0.35/RT - 3dB) or
more conservative approach will be (BW = 0.5/RT).
Regards,
M. Semic
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On
Behalf Of bala
Sent: 26 November 2012 09:25
To: weirsi@xxxxxxxxxx
Cc: si-list@xxxxxxxxxxxxx
Subject: [SI-LIST] Re: Self Impedance Analysis of Power Distribution Network
@Michael Greim
I am considering PDN from source to PCB.I am okay with IR drop and density
concept..
While doing Ac analysis(Self impedance vs Frequency) plot,i have no clue on
upto what frequency it has to be done?Eric bogatin suggestive,it should be
atleast 100MHZ for all PDN.For the device operating at KHZ frequencies,why
should i have to run this upto 100MHZ?
Say for example,I just wanted to know my self impedance curve of ARRIA-2's 2.5V
LVCMOS supply which will consumes 2Amps maximum,and the operating frequency is
125MHZ.And my target impedance is 0.0625ohms..My question is;Should self
impedance of my PDN be below this target impedance till 125MHZ?Why?
Regards
bala
On Sun, Nov 25, 2012 at 10:09 AM, steve weir <weirsi@xxxxxxxxxx> wrote:
> The required frequency range depends on what one is doing. For
> single-ended logic the 5th harmonic is a practical rule of thumb. For
> a 28Gbps channel the 5th harmonic is excessive. The fundamental issue
> is that for just power delivery this is pretty much an issue of Ohm's Law:
> The voltage launched into the Tx line launch will approximate
> |Zlaunch|/(|Zlaunch + Zdriver + Zpdn|). The grid assumption works to
> the extent that the PDN impedance variation of any of the drivers
> looking into the grid is small compared to the load.
>
> Steve.
>
>
> On 11/24/2012 8:16 PM, Brendan Simpson wrote:
> > Bala,
> >
> > I believe you need to simulate not up to the operating frequency,
> > but to
> at least the 5th harmonic as the 5th and above will give you a
> reliable square wave. You should be able to reliably simulate a power
> distribution network as a grid of discrete components with current
> sources switching in the general region that the current drawing
> elements reside. My experience is with PCBs, but my understanding is
> that a similar approach is taken at the chip level. Also of note is
> that the grid analysis method only works correctly when you have whole planes
> for power distro, such as in a PCB.
> >
> > Best Regards,
> > Brendan
> >
> > On Nov 23, 2012, at 6:37 2800AM, bala wrote:
> >
> >> Hi all,
> >> Why self impedance analysis of Power Distribution Network has to be
> >> done upto IO's operating frequency?
> >>
> >> --
> >> bala
> >>
> >>
> >> ------------------------------------------------------------------
> >> 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
> >
> >
> >
>
>
> --
> 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
>
> All contents Copyright (c)2012 IPBLOX, LLC. All Rights Reserved.
> This e-mail may contain confidential material.
> If you are not the intended recipient, please destroy all records and
> notify the sender.
>
> ------------------------------------------------------------------
> 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
>
>
>
--
bala
------------------------------------------------------------------
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:
