An analog front-end with high common-mode rejection ratio and high input impedance for single-lead ECG signal acquisition

This paper proposes an analog front-end circuit applicable to single-lead ECG signal acquisition based on a 0.18 um process. The circuit employs an AC capacitive coupling instrument amplifier (ACIA) with a DC servo loop, significantly improving input impedance. Simulation results indicate an input reference noise of 8.538 uVrms, an ECG signal voltage amplification factor of 30 V/V to 240 V/V, and an input impedance of 4.59 GΩ @15 Hz. The circuit also features low input noise and a high common-mode rejection ratio of 114 dB.