A Multi-channel Biopotential Sensor Interface Based on Gm-linearization Technique with 426-mVpp Linear-Input-Range

Current domain-frequency division multiplexing (CD-FDM) architecture is proposed to alleviate the contradiction between the increasing power consumption per channel and the number of channels for biopotential sensor interface. A transconductance gain amplifier (TGA) with improved linear-input-range is necessary for the CD-FDM architecture to extract the small-amplitude biopotential signal riding on large motion artifacts. Therefore, a multi-channel biopotential sensor interface based on G m -linearization technique is proposed. The interface is implemented in a 180 nm BCD process with an area of 0.847 mm ² . Experimental results show that a 426 mV pp linear-input-range can be achieved. The integrated noise is 1.07 μV rms (0.5-100 Hz) with a NEF of 9.87. A four-channel CD-FDM sensor interface is simulated with real ECG waveforms, demonstrating its potential to be applied in wearable vital signs recording interfered by large motion artifacts.