A fundamental approach to EMI resistant folded cascode operational amplifier design

This paper introduces four design guidelines targeted at improving the susceptibility of circuits to electromagnetic interference (EMI), and applies these to the practical design of folded cascode operational amplifier topologies with a high degree of immunity to conductive EMI injected in their input terminals. Simulations illustrate how an increased immunity to EMI can be obtained using the presented systematic approach. As will be shown, a modified recycling folded cascode topology exhibits an optimal immunity to EMI without overly sacrificing other design parameters.