Fig. 3

Circuit schematics and device integration. The design and schematics of : a The ECoG AFE with controllable gain values of × 300 and × 500, and quasi-DC to 30 Hz bandwidth. b The potentiometric (Pot) AFE with unity gain and bandwidth of 10 Hz. c The amperometric (Amp) AFE consisting of a 100 M Ω transimpedance amplifier (100 mV/nA gain) and 12-bit potentiostat. d The complete system overview presenting the integration of the different AFEs and the PGA stage (shown in red). The signal pathway from the inputs, through the PCB, to the receiver and finally to the cloud is also shown