Design of CMOS based Neuromorphic Sensor Circuit Using Floating Gate MOSFET

Abstract

We presents an Amperometric sensor circuit based on Floating gate technology which emulate spike time dependent plasticity (STDP) of human brain. The cell/neuron membrane is composed of Na and K ions with which cell can learn and adapt in new environment. The proposed circuit stores information in the form of charge at the floating gate (FG) and adaptability/plasticity is simulated in terms of time dependent spikes. The spikes are generated as a cell membrane capacitor’s charging/discharging voltage which in turn, is controlled from sodium and potassium feedback circuits. The circuit have been implemented at 45nm CMOS technology. It generates a modulated voltage spike in response to input stimuli controlling charge at the FG. Inspired from bio-physical neuron model the proposed sensor circuit have been developed with sub-threshold conduction of MOSFETs and thus, circuit operates at nA level current sensitivity. It occupies very less chip area (245µm) and low power consumption (3.3nW) with 1.1V supply. The circuit is highly suitable in bimolecular fields for bimolecular detection.