A Low Noise and Low Power ECG Amplifier Using CMOS Two-stage OTA

Electrocardiogram (ECG) is widely used to record the electrical activity changes of the heart in each cardiac cycle. To make the sensor more environmentally friendly and comfortable to use, lessening the power and noise tends to attract more public attention and discussion. In this paper, we designed a circuit of the ECG amplifier by L TSpice to finally provide low noise and low power practice. We used the three-op-amp circuit architecture with CMOS two-stage OTA and other useful components for the amplifier design. To achieve the targeted value of noise and to reduce power consumption, we updated the input value of resistors and current to have high input impedance for each simulation. The human body circuit was used to evaluate and analyze the properties of the designed circuit. Results show that the measured integrated input-referred noise is 3.63uVrms for the 247Hz frequency range, and the measured power is 4.4uW. The design would be valuable for the future application of ECG sensors in wearable devices.