Implementation of homeostasis functionality in neuron circuit using double-gate device for spiking neural network

The homeostatic neuron circuit using a double-gate MOSFET is proposed to imitate a homeostasis functionality of a biological neuron in spiking neural networks (SNN) based on a spike-timing dependent plasticity (STDP). The threshold voltage (V_th) of the double-gate MOSFET is controlled by independent two-gate biases (V_G1 and V_G2). By using V_th change of the double-gate MOSFET in the neuron circuits, the fire rate of the output neuron is controlled. The homeostasis functionality is implemented by the operation of multi-neuron system based on the proposed neuron circuit. Through the SNN based on STDP using MNIST datasets, it is demonstrated that the recognition rate (~91%) of the SNN with the proposed homeostasis functionality is higher than that (~79%) of the SNN without the proposed homeostasis functionality. Also, the results of the recognition rate with the variations (σ/μ < 0.5) of the synaptic devices and the initial V_th of neuron circuits show a low degradation (1 ~ 3%) in the recognition rate. Thus, it is demonstrated that the homeostasis functionality of the proposed neuron circuit has the immunity to variations (σ/μ < 0.5) of the synaptic devices and the neuron circuits in the SNN based on STDP.