Neuromorphic VLSI second-order synapse

Abstract

The synapse circuit presented here is constructed from a second-order lowpass filter using log-domain techniques. This synapse presents an advantage over those currently available as its output current is proportional to the number of spiking inputs and it can delay the peak current from 0.5-50 ms. Thus, this can be used for temporal coding and to substitute several parallel synapses with one. Measurement results from its implementation in a 0.5 μm ON semiconductor technology are presented.