Abstract
This chapter presents a digital active electrode (DAE) system for multiparameter biopotential signal acquisition. Each DAE is built around an ASIC that performs analog signal processing and digitization by means of on-chip instrumentation amplifiers (IAs), a 12-bit ADC, and a digital interface. Via a standard two-wire I2C bus, up to 16 DAEs (15 channels) can be connected to a commercially available microcontroller, thus significantly reducing the system’s complexity and cost. At the circuit level, each DAE utilizes an innovative “functionally” DC-coupled amplifier for DC and extremely low-frequency biopotential signal measurements while still being AC-coupled. At the system level, a generic common-mode feedforward (CMFF) technique improves the CMRR of an AE pair from 40 dB to the maximum 102 dB.
This chapter is derived from a journal publication by the authors: J. Xu et al., A 15-Channel Digital Active Electrode System for Multi-Parameter Biopotential Measurement, IEEE J. Solid-State Circuits, vol.50, no.9, pp. 2090–2100, Sept. 2015.
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Xu, J., Yazicioglu, R.F., Van Hoof, C., Makinwa, K. (2018). A Digital Active Electrode System. In: Low Power Active Electrode ICs for Wearable EEG Acquisition. Analog Circuits and Signal Processing. Springer, Cham. https://doi.org/10.1007/978-3-319-74863-4_6
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