LAUSR

This brief reviews the principle and design of dynamic range (DR) enhancement techniques for artifact-tolerant biopotential-acquisition ICs. In order to record small input signals without being disturbed by large artifacts, which may arise from motion or stimulation, biopotential-acquisition ICs for wearable devices and bidirectional neural interfaces should have wide DR in addition to low noise and high power efficiency. This review discusses key features of DR enhancement techniques based on three topologies: (1) saturation-free instrumentation amplifier with analog-to-digital converter (ADC), (2) signal-to-noise-and-distortion ratio (SNDR) enhanced ADC, and (3) DR-enhanced ADC with moderate linearity, which are used in state-of-the-art artifact-tolerant biopotential-acquisition ICs.