A DC-connectable multi-channel biomedical data acquisition ASIC with mains frequency cancellation

Abstract

This paper presents an 8-channel biomedical data acquisition ASIC achieving 108dB of dynamic range (DR). Each channel includes a 13bit DAC to compensate differential input offset of up to ±300mV, preventing saturation of the high-gain instrumentation amplifier. Chopper stabilization and DAC-noise low-pass filtering lead to an input-referred noise of 0.8μV <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RMS</sub> . Data processing algorithms, implemented on an FPGA, are employed to remove artefacts due to sudden DAC-switching and to cancel 50/60Hz mains interference including its harmonics. The chip is fabricated in 130nm CMOS, occupying an active area of 2.2mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and consuming 15mW from 1.2V and 3.3V supplies.