From owner-ibis-users@eda.org Tue Oct 23 08:07:29 2001 Received: by server.eda.org (8.12.0.Beta7/8.12.0.Beta7) id f9NF6tGs005094; Tue, 23 Oct 2001 08:06:55 -0700 (PDT) Content-Class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Subject: RE: GND/PWR Clamp Data Collection X-MimeOLE: Produced By Microsoft Exchange V6.0.4712.0 Date: Tue, 23 Oct 2001 11:04:20 -0400 Message-ID: X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: GND/PWR Clamp Data Collection Thread-Index: AcFb0abs6a9ZKFiURKKnl7t6B0YKtAAAEfvi From: "Ingraham, Andrew" To: X-OriginalArrivalTime: 23 Oct 2001 15:06:43.0945 (UTC) FILETIME=[53C13590:01C15BD4] Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by server.eda.org id f9NF6m7n005091 Sender: owner-ibis-users@eda.org Precedence: bulk > I have noticed slight differences in ground clamp curves for 3-state > buffers dependent on whether the data was gathered when the device is > driven high or low ( output hi-Z ). I have found the same to be true > for > power clamp curves. > You can only gather GND Clamp data when the device is (externally) driven Low; and you can only gather POWER Clamp data when the device is driven High; right? I am not sure I understand your question. For 3-state devices, the GND and POWER Clamp curves should be taken with the device in the hi-Z state. The Clamp curves are the only ones used to represent the device when simulated in the hi-Z state, so they need to be accurate. It may be true that the GND Clamp characteristic change when the device is enabled and drives High, or that the POWER Clamp characteristics change when the device is enabled and drives Low. But since the device spends very little, if any, of its time in these regions, I think those differences can always be ignored. Regards, Andy