Comparison of EMI Improved Differential Input Pair Structures Within an Integrated Folded Cascode Operational Transconductance Amplifier

This paper investigates the electromagnetic interference of integrated folded cascode operational amplifiers. In this context seven electromagnetic interference improved differential input pair structures are compared against each other in terms of their susceptibility, but also in terms of their influence on an initial standard reference circuit design and performance. Special focus is laid on not significantly altering these initial specifications that are defined for an integrated folded cascode amplifier, that is used as a case study. Comparisons are made of the investigated structures in terms of electromagnetic interference rejection ratio, area requirement, power consumption, changes in differential and common mode gain, gain-bandwidth product etc.