Design of Transistor Neuron in 180-nm CMOS Technology for Spiking-Based Neural Networks

Document Type : Original Article

Author

Department of Electronics and communication Engineering, Faculty of Engineering, University of Kurdistan, Sanandaj, Iran

Abstract

This paper proposes an analog neuron with the capability of operating under low-voltage supplies. The proposed neuron uses a current-mode low-pass filter with a variable gain to linearly integrate the input spikes onto the membrane capacitance. The spike generator circuit includes a positive feedback loop that not only increases the switching speed but also causes low energy consumption. The use of positive feedback eases the implementation of the frequency adaptation mechanism achieving a realistic time-constant and low power dissipation. An inverter-based voltage comparator is also employed to provide the threshold voltage of the spike generator circuit and re-adjust the membrane potential. Mathematical analyses in the subthreshold region show a first-order linear equation that confirms the structure’s simplicity and linearity of the proposed neuron. The simulation results in the 180-nm CMOS process under a 0.3-V supply voltage report an energy consumption of 176 fJ/spike. In addition, by adjusting the control parameters, the neuron shows different firing patterns such as slow and fast firing, chattering behavior, and frequency adaption mechanism.

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