A highly linear wide dynamic range detector for cell recording with microelectrode arrays

Microelectrode arrays (MEA) are widely used to record extracellular action potential (AP) and local field potential (LFP) in electro-psychological studies. Conventional MEA detectors have low linearity (1%) and limited dynamic range (DR<;;70dB). New immunological applications such as mast cell recoding require higher linearity and wider DR. In this paper, we introduce a new MEA detector architecture with a continuous-time (CT) front-end and a discrete-time (DT) backend to achieve high linearity. We also use chopping and antialiasing RC filter to reduce the noise in the CT front-end and the DT back-end respectively so as to achieve wide DR. The new detector is implemented in a 0.35μm CMOS process. SPICE simulation shows that it achieves 0.07% linearity for 20mV_pp input signal and 0.6μV_rms input-referred noise over 1-200Hz for the LFP signal which results in 81.4dB DR. It can also record the AP signal with 66dB DR. The power consumption is 66.5μW from a 3.3V supply.