EMI-Induced Distortion of Baseband Signals in Current Feedback Instrumentation Amplifiers

The continuous trend toward the miniaturization of modules, comprising high sensitive devices alongwith noisy circuits likewireless transceivers and digital core blocks, has led us to investigate the effect of disturbances on analog front-end circuits used in system-in-package modules. In this context, this paper focuses on the distortion of radio frequency interference in CMOS current feedback instrumentation amplifiers like those used in MEMS readout circuits. The way baseband signals are distorted by such amplifiers, when the interference is superimposed onto the input signals, is analyzed referring to a math model, to computer simulations and to measurements carried out on a test chip designed and fabricated specifically for this purpose.