[SI-LIST] Re: How to measure the On Die decupling capacitor value ?
- From: Hermann Ruckerbauer <hermann.ruckerbauer@xxxxxxxxxxxxx>
- To: si-list@xxxxxxxxxxxxx
- Date: Tue, 14 Sep 2010 21:41:10 +0200
just as I have read point no 1 to 3 :
in this case of course it would be interesting which device it is (I
have not followed this thread) ... if it is a DRAM memory device it
might use it's storage capacitor for Decoupling and this might behave
different to the mentioned kinds of capacitors ...
Hermann
EKH - EyeKnowHow
Hermann Ruckerbauer
www.EyeKnowHow.de
Hermann.Ruckerbauer@xxxxxxxxxxxxx
Veilchenstrasse 1
94554 Moos
Tel.: +49 (0)9938 / 902 083
Mobile: +49 (0)176 / 787 787 77
Fax: +49 (0)3212 / 121 9008
schrieb Cosmin Iorga:
> A few more comments:
> On-chip decoupling capacitance typically consists of:
>
> 1. Device capacitance: this is PN junction type capacitance that varies with
> the
> bias voltage.
>
> 2. �Metal to metal� capacitance on metal layers, which looks like the
> classic
> parallel plate capacitors and does not depend on bias
> 3. Decoupling MOS gate type capacitors, which depend on bias voltages and
> frequency
>
> These are not ideal capacitors, and they have ESL, ESR, and resonant
> frequency.
> Also, the on-chip capacitors decouple high dI/dt transients that cannot pass
> through the bond wire inductance into the external PDN, so if you use a low
> frequency measurement technique you may not know what impedance these
> capacitors
> have at their intended operating frequency. The only efficient method I know
> to
> determine the on-chip capacitance of an arbitrary integrated circuit is
> modeling
> and correlation with measurements on a chip/package/PCB structure if you have
> any (eval board will work just fine).
>
> Cosmin Iorga,
> NoiseCoupling.com
> http://www.noisecoupling.com
>
>
>
>
>
> ________________________________
> From: yardala <yardala@xxxxxxxxx>
> To: si-list@xxxxxxxxxxxxx
> Sent: Fri, September 10, 2010 7:15:21 PM
> Subject: [SI-LIST] How to measure the On Die decupling capacitor value ?
>
> Hi, All
> Can I measure the value of On Die Decoupling capacitor use only capacitor
> meter
> probing at pin Vdd and Vss ?
>
> When I use meter to measure the value of core logic are few nH and unstable,
> the value of I/O power are several hundred pF.
>
> Does these value make sense ? does it good enough , or any other methods are
> suggest ?
>
> Does the bonding wire effect the capacitor value ?
>
> Thanks!
>
> Yardala
>
>
> ------------------------------------------------------------------
> 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
>
>
>
------------------------------------------------------------------
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:
