Hi All, If you use active probes to measure today's high speed signals, there are significant design assumptions from one probe to another and different probes can give significantly different results on the same signal. Understanding the differences is essential to avoid time wasting lab mistakes. My Technical Tidbit on this subject is posted at http://emcesd.com with the link being the diagram at the bottom of the home page. Abstract: As circuits have become faster, active scope probes have become more sophisticated in order to measure today's very high speed signals. At the same time, probe loading of measured signals has become more of an issue. The question of whether to display the signal at the probe tip or to estimate what the signal was without the probe is an important one that designers must take into account. Implications of this choice are discussed. I have also included an in-depth audio-visual tutorial dealing with this topic on my subscription site, linked in the article (broadband connection and subscription needed). Doug -- ------------------------------------------------------- ___ _ Doug Smith \ / ) P.O. Box 1457 ========= Los Gatos, CA 95031-1457 _ / \ / \ _ TEL/FAX: 408-356-4186/358-3799 / /\ \ ] / /\ \ Mobile: 408-858-4528 | q-----( ) | o | Email: doug@xxxxxxxxxx \ _ / ] \ _ / Website: http://www.dsmith.org ------------------------------------------------------- ------------------------------------------------------------------ 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 FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org 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