Tunneling-based CMOS Floating Gate Synapse for Low Power Spike Timing Dependent Plasticity

We propose a CMOS architecture for spiking neural networks with permanent memory and online learning. It uses a three-transistors synapse with a floating node that stores the synaptic weight, programmed by using only Fowler-Nordheim tunneling current in the pA range for ultra-low power operation. A neuron with a conditioning circuit programs the floating gate synapse following the spike timing dependent plasticity rule. Simulations using a standard 150 nm CMOS process show the online learning capabilities of the architecture.