Ultra-Low Power and Low-Leakage Subthreshold CMOS Neural Circuit Design

In this paper, we present a neural circuit structure that includes synapse and neuron circuits designed to mimic the behavior of a biological brain. The circuits are implemented with a 0.6 V supply voltage, operating in the subthreshold region to achieve high energy efficiency. The Leaky Integrate-and-Fire (LIF) neuron design achieves an energy consumption of only 375 fJ per spike, while the synapse circuit achieves biologically realistic time constants (on the order of tens of milliseconds) by utilizing small capacitors in the femtofarad range (200 fF). To mitigate leakage current, a key challenge in sub-micron CMOS technologies, we employ 130-nm UMC low-leakage transistors.