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