A 96 dB Input Dynamic Range Galvanic Skin Response Readout IC With 3.5 pA_rms Input-Referred Noise for Mental Stress Monitoring

This paper presents a low-noise, low-power galvanic skin response (GSR) sensing circuit capable of simultaneously measuring skin conductance level (SCL) and skin conductance response (SCR) for psychological stress monitoring. The circuit incorporates second-order sub-ten-hertz filters that suppresses out-of-band interference and a programmable gain amplifier (PGA) to accommodate signals of varying magnitudes. Additionally, a dynamic range adjustment mechanism optimizes the primary amplifier's operating range based on real-time SCL readings. The design achieves a 96.4 dB dynamic range with an input-referred noise of only 3.47 pA_rms within 0.5-5 Hz under optimal conditions. These advancements significantly enhance measurement accuracy and robustness for wearable stress monitoring and real-time biofeedback applications.