Biopotential Readout Front-End ASICs

The readout front-end ASIC of Chap. 3 requires a large number of off-chip components and has a relatively large current consumption. Although, its usage can considerably improve the size of the existing biopotential acquisition systems, the relatively large current consumption still limits the power autonomy of the system. Therefore, further improvement is possible if the number of external components and the power dissipation can be reduced.

This Chapter presents a single-channel ExG ASIC and an eight-channel EEG readout front-end ASIC. The main focus is to minimize the power dissipation of the building blocks of the ASICs, while maximizing the performance such as higher CMRR and reduced 1/f noise. Except for the number of channels the building blocks of the two ASICs of this Chapter are similar, where each channel consists of an AC coupled chopped IA (ACCIA), a chopping spike filter (CSF), and a programmable gain stage (PGS). The single-channel ExG ASIC can be used for EEG, ECG, and EMG acquisition applications and the eight-channel EEG ASIC is dedicated to EEG acquisition applications.