A mixed-domain behavioral model's extraction for digital I/O buffers

The paper presents a novel extraction procedure based on the frequency domain formulation of the current-charge (I-Q) behavioral model for digital I/O buffers/drivers output admittance followed by a time domain extraction of the predriver's nonlinear dynamic functions. The large signal model's functions of the drivers' output admittance are derived from the bias-dependent scattering, or S-parameters, measurements. This easy and fast extraction method allows the accurate generation of the data-based model from automated and straightforward measurements. The extracted model's functions are implemented as lookup tables (LUTs) and the behavioral model is validated in typical SI scenario.