I have just been asked a question about how to extract [Ramp] for a differential buffer for IBIS. As I was trying to make sure that I give the correct answer I realized that the IBIS spec doesn't deal with this question. The [Ramp] keyword doesn't say anything about how to connect Rload when extracting the data, and Chapter 9 only talks about the good old, rail-to-rail CMOS buffers, suggesting that Rload should be connected to Vcc and GND. This may not work for a low voltage swing true differential buffer any more. What is the official rule for Rload in [Ramp] for such differential buffers? I am sending this to the IBIS-ATM list as well because this may be another point on the list of IBIS overhaul. These types of buffers have been around for years, and I am wondering why we are neglecting them in the spec... Arpad =========================================================