Analytic investigations on the susceptibility of nonlinear analog circuits to substrate noise

[摘要] This work deals with the conducted susceptibility of nonlinear analogcircuits with respect to substrate noise. The substrate coupling mechanism ismodeled by a passive three-terminal network that is obtained by means of thefinite element method with a subsequently performed model order reduction.Applying this substrate model to the bulk terminal of MOS transistors inintegrated analog circuits, it is possible to examine the influence ofsubstrate noise on the circuit's functionality. By means of a block-orientedapproach, analytic expressions for the output behavior of the circuits arefound. The utilized multi-input Wiener model separates the linear dynamicfrom the nonlinear static circuit properties. Due to this separation thefrequency response of both signals, i.e.,input signal and substrate noise,respectively, can be identified, and hence, the frequency range in which thecircuit is most susceptible to substrate noise. Since the nonlinear staticbehavior of each MOS transistor depends on two signals, truncatedmultivariate Taylor series expansions of the nonlinear elements are performedon the basis of the EKV model description (Enz et al., 1995). The proposedmodeling is illustrated by a simple example.

[学科分类] 电子、光学、磁材料