Can LSE Reduce Noise in Sensing Applications?

This work reports an experimental investigation of Large Scale Excitation (LSE) in sensing applications. This technique aims at mitigating flicker noise by suppressing its originating, signal-dependent, phenomena. Differently from modulation/chopping, which is not effective in these situations (flicker noise is modulated just as the signal is), LSE aims at switching on/off the source of signal generation without leaving enough time for carrier trapping or mobility changing, so blocking random telegraph noise phenomena which build up 1/f noise. As 1/f noise appears both in transistors and thin-film resistors, which are both key elements in the front-end of various sensors types, this work, after providing a simplified model for the scenario, experimentally verifies LSE. Results confirm the possibility of consistent flicker noise reduction in MOS transistors, by as much as a factor 3.3, whereas no flicker noise reduction is observed on piezoresistors, hinting that the source of 1/f is here a different process.