Fast-settling technique under large electrode offset in integrated biopotential amplifiers

This paper presents a fast-settling technique to reduce the settling time in response to large electrode offset voltage (EOV) in biopotential amplifiers. Settling response in a prototyped capacitively-coupled instrumentation amplifier is significantly accelerated by the proposed DC component feed-forward path; meanwhile the traditional feedback path is also employed to take care of residue DC offset voltage. Implemented in a 0.18 μm CMOS process, the proposed architecture can automatically settle down ±200 mV electrode offset within only 6.4 seconds without extra out-of-chip observation or manually control. Thereby in practical usage, continuous-time monitoring with less long-period DC settling interference is possible, leading to better signal recording robustness.