New circuit modeling of operational amplifiers

A description is given of the design of two macromodels for the 741 operational amplifier to be used for computer code simulation of electromagnetic interference (EMI) effects. These macromodels are designed with the ability to work outside the nominal frequency bandwidth of the real circuit in order to simulate the consequences of small and large amplitude signals representing EMI effects. The design starts with the analysis (via numerical simulations) of the full device level model. After the macromodel has been defined, its behavior is adjusted by comparison to experimental measurements on different circuit configurations and interference sources. Measured and simulated results are in agreement