An accurate AC characteristic table look-up model for VLSI analog circuit simulation applications

A new accurate table look-up method is presented for modeling both I-V characteristics and C-V and/or Q-V characteristics of deep submicron MOSFETs for VLSI analog circuit simulation. Based on the linear and quadratic isoparametric shape functions, the proposed table lookup approach can accurately model complicated AC characteristics of MOSFETs. The charges and capacitances derived through integration of C-V characteristics and differentiation of Q-V characteristics match the original measured data at table grid points. The proposed table lookup model accurately fits the deep submicron MOSFET´s I-V characteristics as well. It is shown that AC small-signal and transient simulations of CMOS operational amplifier circuits using the proposed table lookup approach are exactly matched to those with the Ward and Dutton model in the simulation program with IC emphasis (SPICE)2 when AC table data are generated from the Ward and Dutton model