Analog circuit for synapse neural networks VLSI implementation

In this paper the author presents an analog VLSI circuit to implement the synapse operation in artificial neural network systems. This circuit is a two-quadrant (or four-quadrant) analog multiplier. The output of the synapse circuit is in current and it is proportional to the multiplication of two input voltages: the weight voltage and the pattern information input voltage (or the output voltage of the neuron). The main feature of the multiplier is the high value of the weight voltage range, which varies between the ground voltage and the supply voltage [0:Vdd].