Hello, I have some questions about C_Comp parameter in IBIS models. I am trying to resolve some issues for IBIS models of high frequency differential output buffers. I am trying to compare my SPICE model transient simulations with the IBIS model I generated for a differential output buffer. At low frequencies (eg ~ 100MHz), the SPICE and IBIS model output simulation waveforms correlate closely. But at higher frequencies (>400MHz), the SPICE and IBIS model simulations don't match as well. I am trying to see if the mismatch is due to the C_comp parameter, or if this is just a limitation of IBIS models not being able to capture high frequency effects. 1. How IBIS simulators use the C_comp parameter during simulations? 2. Don't the V-T tables and ramp information already take into account the effect of C_comp? 3. What does the C_comp parameter exactly represent? -should it include die routes, pad capacitance, etc? 4. How should it be measured? 5. Should C_comp be measured in a special manner for differential buffers like LVDS buffers? I would appreciate your response. Thank you, -Chitiz Mathema Cypress Semiconductor -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. -------------------------------------------------------------------- |For help or to subscribe/unsubscribe, e-mail majordomo@eda-stds.org |with the appropriate command message(s) in the body: | | help | subscribe ibis <optional e-mail address, if different> | subscribe ibis-users <optional e-mail address, if different> | unsubscribe ibis <optional e-mail address, if different> | unsubscribe ibis-users <optional e-mail address, if different> | |or e-mail a request to ibis-request@eda-stds.org. | |IBIS reflector archives exist under: | | http://www.eda-stds.org/pub/ibis/email_archive/ Recent | http://www.eda-stds.org/pub/ibis/users_archive/ Recent | http://www.eda-stds.org/pub/ibis/email/ E-mail since 1993Received on Fri Aug 24 16:34:55 2007
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