Don't worry about the way I measure the spikes. I do use J-Fet buffered 1.5GHz probes with the miniature GND spike pin which is right next to the probe signal pin. On my PCB, I placed GND & supply test points around the PLD just for such an emergency.
I do know that when measuring any signals here, even stuff in the 10 MHz range, the conventional 10x probes suck royally. Scope snapshot coming in 2 hours... ____________ Brian Guralnick [EMAIL PROTECTED] Voice (514) 624-4003 Fax (514) 624-3631 ----- Original Message ----- From: "Richard Sumner" <[EMAIL PROTECTED]> To: "'Protel EDA Forum'" <[EMAIL PROTECTED]> Sent: Monday, September 09, 2002 2:24 PM Subject: Re: [PEDA] off topic supply SOS > Brian, > > Measuring spikes on the supply lines is not trivial. Where you put the > scope probe ground is everything. The best way to measure is with a > differential probe, placed across the power pins of the chip in question. > Anything less may not give you the true picture. > > Don't misunderstand, this is not a criticism, but a heads up. Be alert when > making this kind of measurement. > > Richard > > > > Cheesecote Mountain CAMAC, 24 Halley Drive; Pomona, NY 10970 > voice: 845 364 0211, fax: 845 362 6947, www.cmcamac.com > > > ************************************************************************ > * Tracking #: FD6D883A80FDAD4CBE28A8F34C309861BFE3E3E7 > * > ************************************************************************ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/[email protected] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
