This is a little off the SI topic related to these FET switches, but I would also want to understand how I select one of these clocks, by enabling one these switches, without initially causing a sliver of a clock pulse to propagate out to my flops. Jim Peterson Honeywell -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Scott McMorrow Sent: Friday, May 30, 2008 9:19 AM To: steve weir Cc: ravi.potana@xxxxxxxxx; si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: Quick switch Ravi To follow on with what Steve has said, most FET switch packages do not=20 have adequate package grounding. Since the substrate is normally=20 grounded, this poses a problem, since there is parasitic capacitive=20 coupling between each switch and the substrate. These are fairly easy=20 devices to model in SPICE, and many manufacturers provide accurate=20 models. IBIS models, however, cannot adequately model these devices. regards, Scott Scott McMorrow Teraspeed Consulting Group LLC 121 North River Drive Narragansett, RI 02882 (401) 284-1827 Business (401) 284-1840 Fax http://www.teraspeed.com Teraspeed(r) is the registered service mark of Teraspeed Consulting Group LLC steve weir wrote: > An NFET or CMOS switch in a package has parasitics like any other=20 > device. If you model and work within the limitations of those=20 > parasitics you shouldn't have any unwelcome surprises. If you pretend > that the device is without parasitics you can easily make designs that > run into problems. > > Steve > ravi.potana@xxxxxxxxx wrote: > =20 >> Hello All, >> =20 >> Please let me know if anyone has used Quick switch (FET based) on clock >> with frequency 125MHz for muxing operations and seeing any SI issues on >> the clock line after passing through the FET Switch.=20 >> =20 >> regards >> Ravi >> Please do not print this email unless it is absolutely necessary.=20 >> >> The information contained in this electronic message and any attachments to this message are intended for the exclusive use of the addressee(s) and may contain proprietary, confidential or privileged information. If you are not the intended recipient, you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately and destroy all copies of this message and any attachments.=20 >> >> WARNING: Computer viruses can be transmitted via email. The recipient should check this email and any attachments for the presence of viruses. The company accepts no liability for any damage caused by any virus transmitted by this email.=20 >> >> www.wipro.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 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 >> >> >> =20 >> =20 > > > =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: =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