A 10-bit resolution wide dynamic range detector for cell recording with microelectrode arrays

摘要

Microelectrode arrays (MEA) are widely used to record extracellular action potential (AP) and local field potential (LFP) in electropsychological studies. Conventional MEA detectors have <7bit linearity and 48∼60dB dynamic range (DR). However, new immunological applications such as mast cell recoding require high linearity and wide DR. In this paper, we introduce a new MEA detector architecture with a continuous-time (CT) front-end and a discrete-time (DT) back-end to achieve high linearity. We also use chopping and an anti-aliasing low pass filter to reduce the noise in the CT front-end and the DT back-end respectively so as to achieve a wide DR. The detector is implemented in a 0.35µm CMOS process. SPICE simulation shows that the new detector achieves 0.06% linearity for 20mVpp input signal and 0.98µVrms input-referred noise over 0.8–400Hz for LFPs, which results in 77dB DR. The new detector can also record APs with 63dB DR. The power consumption is 74µW from a 3.3V supply.