Failures induced on bipolar operational amplifiers from electromagnetic interferences conducted on the power supply rails

In this work, we study the effects of electromagnetic interference conveyed to the supply rails of integrated bipolar operational amplifiers. In particular, with reference to the well known /spl mu/A741 topology, we show that amplifiers undergo very strong failures when subjected to EMI conveyed to the negative supply, while they are only moderately sensitive to interference conveyed to the positive supply. Finally, on the basis of detailed circuit analyses and simulations, we report the physical origin of such failures.