[SI-LIST] Re: PDN related
- From: Scooby Doo <si.scooby@xxxxxxxxx>
- To: "Lynne D. Green" <lgreen22@xxxxxxxxxxxxxx>
- Date: Mon, 15 Mar 2010 10:42:18 -0700 (PDT)
Hi Lynne,
This is what exactly what is wanted to ask. If the slew rate is 1v/ns, then my
0.1uF capacitor value (designers blindly using value) will not support due to
existance inductive nature at that frequency.
So kindly give some reference / notes so that choosing right value.
--- On Mon, 3/15/10, Lynne D. Green <lgreen22@xxxxxxxxxxxxxx> wrote:
From: Lynne D. Green <lgreen22@xxxxxxxxxxxxxx>
Subject: [SI-LIST] Re: PDN related
To: "Scooby Doo" <si.scooby@xxxxxxxxx>
Cc: "SI LIST" <si-list@xxxxxxxxxxxxx>
Date: Monday, March 15, 2010, 5:20 PM
Depends on the frequency range where you need PDN clean.
If it is a wide range (generally true) then one would use
more than one value of capacitor. Remember, capacitor
impedance increases at high frequency due to inductive
package effects.
Lynne
"IBIS training when you need it, where you need it."
Dr. Lynne Green
Green Streak Programs
http://www.greenstreakprograms.com
425-788-0412
lgreen22@xxxxxxxxxxxxxx
Scooby Doo wrote:
> Hi SI Experts,
>
>
> I have a question reg PDN.
>
> Suppose an FPGA has 100 I/O pins with 10 VCCO/Gnd pairs. So an average of 10
> I/O pins for 1 VCCO/Gnd pair. Assume each I/O pin driving 10pf load.
>
> My qn is, to make the clean PDN, is it enough to provide 100pf of capacitor
> to each Vcc/Gnd pair?
>
> I am not convinced with blindly provinding 0.1uF cap to Vcco pins.
>
> kindly clarify.
>
> Thanks in advance for your valuable feedback.
>
> Rajesh
>
>
------------------------------------------------------------------
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
------------------------------------------------------------------
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:
