New macromodels and measurements for the analysis of EMI effects in 741 op-amp circuits

摘要

Presents the design of two macromodels for the 741 op-amp that prove trustworthy in simulating the consequences of high-frequency, large-amplitude sinusoidal voltages that represent EMI (electromagnetic interference) effects and are applied to the input of inverting and noninverting amplifiers. One of the macromodels accounts for power supply voltage change, reproduces correct voltage waveforms at the main nodes of the full circuit, and gives rise to computer time saving factors of 5 or more in comparison with full device-level simulations. The other comprises the minimum number of components necessary to estimate the DC output voltage only and reduces the simulation time by a further factor of about 5. Extensive experimental results were obtained from laboratory measurements and are compared with the numerical simulations.