Nonlinear effects of radio-frequency interference in operational amplifiers

In this brief, the susceptibility of operational amplifiers to radio frequency interference (RFI) is studied by a new analytical model. The proposed model, in particular, points out the dependence of the RFI induced dc offset voltage shift in operational amplifiers on design parameters and parasitics, giving both a good insight into the nonlinear mechanisms involved in the phenomenon and a support to integrated circuit designers in order to develop high immunity operational amplifiers. The validity of the proposed approach is discussed comparing model predictions with the results of computer simulations and experimental measurements.