[SI-LIST] Re: Measuring Power supply Ripple and Noise

  • From: Istvan Novak <istvan.novak@xxxxxxx>
  • To: Jaison Fernandez <jaisonf@xxxxxxxxxxxxxxx>
  • Date: Thu, 13 Nov 2008 08:17:21 -0500

Jaison,

If you really want repeatable characterization, I would suggest 
measuring the impedance profile in
the frequency domain.  This, however, would require some pre-defined 
means for instrument
connection, so if you already have a board, you may be limited to low 
frequencies in terms of
self-impedance characterization.  To check the time-domain noise on a 
running board, you can
use oscilloscopes and you can make different connections dependent on 
the frequency range
you are after.  To check the low-frequency noise (up to about 10 MHz), 
simple pig-tail soldered
connections are good, and you should see for instance the DC-DC 
converter output ripple.
For this, the connection can be made across components.  For 
high-frequency measurements you
should not connect the cable or probe across any component as it may 
severely color the result.

You can find the basics in "Frequency Domain Power Distribution 
Measurements - An Overview",
posted at http://home.att.net/~istvan.novak/papers.html, or you can get 
much more details in
the book: Frequency Domain Characterization of Power Distribution 
Networks, Artech House.

Regards,

Istvan Novak
SUN Microsystems

Jaison Fernandez wrote:
> Hai all,
> I am trying to characterize the power integrity of of a board (that having a
> system clock running at 400Mhz and DDR memory)
> What is the type of probe (Single ended or differential) is best suited for
> measuring power supply ripple and noise in the board.(I am using Tek GHz
> Oscilloscope for this purpose)
> Can any one give any document regarding measuring power integrity of a
> board.   
>  
>
>  
>
> With Warm Regards,
>
> JAISON FERNANDEZ 
>
>  
>
>
>   

------------------------------------------------------------------
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
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: