[SI-LIST] Re: Few analog power supplies, where to short it.
- From: "Bill Chen" <billchen@xxxxxxxxxxx>
- To: <yehuday@xxxxxxxxxxxx>, "Silist (E-mail)" <si-list@xxxxxxxxxxxxx>
- Date: Thu, 21 Mar 2002 09:38:54 -0800
Hi Yehuday,
It all depends on the power noise rejection/performance requirement /
noise generation of the analog circuits of different power domains
on your die.
If all your onchip analog circuits on different power domains have
same (or similar) power noise rejection characteristics/requirement and they
also generate similar amount of power noise, tie all analog
power supplies together make good sense. By doing that,
you may share both package level and board level decoupling.
On the other hand, if the power noise rejection characteristics/requirement
are very different, you may want to have the analog power supplied
separate on package, so you can have flexibilities to put different
amount of decoupling on your boards (give you cost advantage
by using right amount of decoupling caps where needed).
Thanks!
Bill Chen
Andiamo Systems
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx]On
Behalf Of Yehuda Yizraeli
Sent: Thursday, March 21, 2002 4:01 AM
To: Silist (E-mail)
Subject: [SI-LIST] Few analog power supplies, where to short it.
Hi,
I have few analog power supplies for a chip to be packed in a BGA
package. Two options are considered. The first is to short all analog
supplies on the BGA and have a better/bigger supply plane. The second option
is to short it on the board. Since we are talking about a BGA package, the
inductance of the package is very small.
1) Can I say, based on the above, that the noise introduced between analog
domain if its being shorted on package is the same to the option in which
its being shorted on board?
2) Which option will introduce less noise between supplies, i.e. ?
3) Which option is better in decoupling noise (decoupling of noise generated
in this power supply)
any input and/or reference is welcomed with thanks
in advance!!!
yehuda
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Yehuda D. Yizraeli
Mysticom LTD E-mail :
yehuday@xxxxxxxxxxxx
1st Zoran st, #6 Direct Tel: 972-9-8636-497
P.O.B. 8364, Netanya 42504 Operator : 972-9-8636-465
ISRAEL Cellular :
972-57-556-335
Fax :
972-9-8636-466
<http://www.mysticom.com>
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
------------------------------------------------------------------
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 archives are viewable at:
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
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 archives are viewable at:
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
Other related posts:
