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

Digital Suppression of EMI-Induced Errors in a Baseband Acquisition Front-End including Off-the-Shelf, EMI-Sensitive Operational Amplifiers

“…These results confirm the effectiveness of the proposed approach, and an EMI immunity outperforming previously commercial EMI hardened opamps [53] and EMI-robust opamp circuits proposed in the literature [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42], which require custom analog ICs and a significant design effort.…”

“…While the opamp susceptibility is normally addressed either by on-chip filtering or by ad hoc opamp circuits [26][27][28][29][30][31][32][33][34][35][36][38][39][40][41][42], the reconstruction of the original information from the sensor by post-processing the corrupted digital output stream from the ADC will be addressed in this paper.…”

“…In most EMI-robust opamp circuits proposed so far in the literature [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44], a reduced susceptibility to EMI is achieved at integrated circuit level either by filtering or by filtered replica stages [29,30,[35][36][37]40,41,43], or by ad-hoc input differential stages, in which the EMI-induced offset voltage and the low-frequency demodulated components resulting from RF rectification are mitigated by active device degeneration [28,39], or ideally cancelled by compensating asymmetries in EMI propagation [30][31][32]38] or, finally, by the compensation of different nonlinear mechanisms [21,30,33,34,37,41,42].…”

“…In spite of many significant improvements observed in the last years [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43] the EMI-robust opamp circuits presented to date still suffer of several limitations. First, EMI immunity invariably requires non-conventional topologies and careful ad hoc analog design; second, it can be easily impaired by process variations and device mismatch; third, it is often traded off with baseband performance and/or with chip area and power.…”