A 1.83 μW, 0.78 μVrms input referred noise neural recording front end

This paper describes a neural recording front end for both Local Field Potential (LFP) and Spike Potential (SP) recordings, which range from 0.1 Hz ~ 200 Hz and 200 Hz ~ 10 kHz, respectively. Based on the capacitively-coupled chopper instrumentation amplifier (CCIA) topology, a ripple reduction loop (RRL) is used to suppress the chopping ripple. A DC servo loop (DSL) that utilizes pseudo-feedback to achieve a very small unity gain bandwidth with reduced capacitor size while consuming only 12 nA is proposed. The proposed CCIA is implemented in a standard 0.18 μm CMOS process. Simulation results show that with a total power consumption of 1.525 μA from a 1.2 V supply, a NEF of 2.73 (LFP) and 2.6 (SP) can be achieved.