Impact of the Leakage Current of an AND-type Synapse Array on Spiking Neural Networks

In this paper, we analyze the impact of the leakage current of an AND-type synapse array on a spiking neural network (SNN). In order to evaluate the firing rate modulation affected by the leakage current of a synapse array, the electrical characteristics of a fabricated dual-gate synapse are measured and modeled. A SPICE circuit simulation shows a severe change in the firing rate in the SNN, and a system-level simulation with MNIST datasets exhibits frequency-dependent performance degradation due to the leakage current. Compared to a case with negligible leakage current, a 6.98% accuracy loss at 50 kHz of input frequency, which is the firing rate of conventional CMOS neurons.