09/27/04 *Other brands and names are the property of their respective owners Page 1 Objective: match FD response of IBIS to transistor buffer IBIS and Transistor models analyzed using S-parameters IBIS model constructed using IBIS Center, templates C_comp at typical calculated at 0.51 pF HSPICE , CosmosScope used for analysis.LIN with 3 P-elements (Ports), each with Zo=50 Ω Ports 1, 2 represent “pulldown” and “pullup” Z, respectively Port 3 has a DC bias of 1.8 V, and represents supply Z Models “float” – 100e6 Ω resistors connect to ideal “0” BIRD95 Analysis Method PD PU IO Port 2 Port 1 Port 3 By Michael Mirmak

09/27/04 *Other brands and names are the property of their respective owners Page 2 Results - Transistor

09/27/04 *Other brands and names are the property of their respective owners Page 3 Results – 100% PD C_comp

09/27/04 *Other brands and names are the property of their respective owners Page 4 Results – 50/50 PU/PD C_comp

09/27/04 *Other brands and names are the property of their respective owners Page 5 We take data on Port 1, Port 2 and Port 3 We need Zpdn but do not measure it directly Use Z-parameter conversion to obtain R+jX series RC Model Version 1 PD PU IO Port2 Port1 Port3 Z PDN Z PU Z PD

09/27/04 *Other brands and names are the property of their respective owners Page 6 Build model of transistor impedances All three ports are critical! Add elements to IBIS model to match transistor Ensure split C_comp ratio is set, understood for match Compare vs. transistor and all-PD C_comp Add I-T table behavior This will account for crowbar currents Use AMS languages to match behavior See Arpad’s VHDL-AMS model results Next Steps