Charles- Here are a couple more relevant ones I missed in my previous message: http://home.att.net/~istvan.novak/papers/designcon99.pdf http://home.att.net/~istvan.novak/papers/designcon99_slides.pdf -Ray -----Original Message----- From: Ray Anderson=20 Sent: Thursday, July 12, 2007 10:13 AM To: Grasso, Charles; heinrich.smith2005@xxxxxxxxx; si-list@xxxxxxxxxxxxx Cc: Ray Anderson Subject: RE: [SI-LIST] Re: My way to Kill ripple noise on the power rail Charles- Here are links to some relevant papers on the topic: http://home.att.net/~istvan.novak/papers/DC03-East_HP-TF1_SUN.PDF http://home.att.net/~istvan.novak/papers/dc2000_rev.pdf http://home.att.net/~istvan.novak/papers/dc2000_slides.pdf http://www.si-list.net/files/published/sun/cpmt_2001.pdf http://www.si-list.net/files/published/sun/asme_2001.pdf Istvan's DC2000 papers are especially well done and on topic. Regards, -Ray Raymond Anderson Senior Signal Integrity Staff Engineer Advanced Platforms Group Advanced Products Division Product Technology Department Package Design Engineering Xilinx Inc. 2100 Logic Drive San Jose, California 95124 (408) 626-6277 -----Original Message----- From: Grasso, Charles [mailto:Charles.Grasso@xxxxxxxxxxxx]=20 Sent: Thursday, July 12, 2007 10:01 AM To: Ray Anderson; heinrich.smith2005@xxxxxxxxx; si-list@xxxxxxxxxxxxx Cc: Ray Anderson Subject: RE: [SI-LIST] Re: My way to Kill ripple noise on the power rail Thanks Ray! I had a quick look at the papers listed in the Si-List archives and didn't see any that specifically address measurement techniques. Can you point me in the right direction? Best Regards Charles Grasso Compliance Engineer Echostar Communications Corp. Tel: 303-706-5467 Fax: 303-799-6222 Cell: 303-204-2974 Pager/Short Message: 3032042974@xxxxxxxxx Email: charles.grasso@xxxxxxxxxxxx -----Original Message----- From: Ray Anderson [mailto:ray.anderson@xxxxxxxxxx]=20 Sent: Thursday, July 12, 2007 10:56 AM To: Grasso, Charles; heinrich.smith2005@xxxxxxxxx; si-list@xxxxxxxxxxxxx Cc: Ray Anderson Subject: RE: [SI-LIST] Re: My way to Kill ripple noise on the power rail Charles- For measuring low impedances such as found in PDNs, S21 measurements are much more effective than S11 measurements. Using S11 it is difficult to measure very low Z accurately due to probing parasitics (L primarily). See some of the papers on the topic written a few years back by Istvan Novak and also Larry Smith and myself. Regards, -Ray -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Grasso, Charles Sent: Thursday, July 12, 2007 9:13 AM To: heinrich.smith2005@xxxxxxxxx; si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: My way to Kill ripple noise on the power rail Nice analysis. I suppose the trick is step3. Using a VNA can be tricky when measuring a low impedance plane. Also typically folks measure S11 not S21. Typically how do you choose the two measurement points? Best Regards Charles Grasso Compliance Engineer Echostar Communications Corp. Tel: 303-706-5467 Fax: 303-799-6222 Cell: 303-204-2974 Pager/Short Message: 3032042974@xxxxxxxxx Email: charles.grasso@xxxxxxxxxxxx -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Heinrich.Smith Sent: Thursday, July 12, 2007 8:22 AM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] My way to Kill ripple noise on the power rail About one years ago, i had ripple noise problem when the specific test program was enable. I fixed it by measurement and simulation. My way to Kill ripple noise on the power rail shows as below: step 1: measure the ripple voltage by the scope at the specific test condition. the test condiction could be normal operation of the system or running stress program or stimulate 101010 on each bit to busy the bus traffic... Anyway, The first job is to capture the biggest ripple voltage that you are suffering .I assume it as delta-v (I am used to investigate the waveform from ms->us->ns by tunning time scale) step 2: To see the repeated period on time scale and judge the ripple is contributed mostly by x MHz. step 3: To Get power rail's Z-profile by VNA(S21->Z21),pick up the Z value at x MHz.I assume its value is z. So i get an estimate delta current at x MHz, i=3D3D delta-v/z step 4: If i want to reduce delta-v to delta-v",i define a Z_target as delta-v"/i , "i" is gotten by step 3. step 5: You can use the Z_target(gotten from step 4) as our goal to reduce ripple voltage at x MHZ and set this criteria on your PI simulation tool like Cadence SQ-PI,Sigrity PowerSI,or Ansoft SI-Wave. step 6: After the simulation work of step 5, you should get the decap strategy include value,number, and placement.(note,it is effective only around x MHz). then, re-work your board and measure ripple noise again. After you successfully kill the ripple voltage at x MHz, you will more likely to see the secondary ripple voltage. The same, follow the above procedure to kill it again till the overall ripple noise is under the spec. That's my experience for you reference. Any comments and possible improvement are welcome to share with me. Thank you! -Heinrich ------------------------------------------------------------------ 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: =3D20 //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 =3D20 ------------------------------------------------------------------ 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: =20 //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 =20 ------------------------------------------------------------------ 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