Amplifier-based MOS analog neural network implementation and weights optimization

Neural networks are achieving state-of-the-art performance in many applications, from speech recognition to computer vision. A neuron in a multi-layer network needs to multiply each input by its weight, sum the results and perform an activation function. This paper presents a variation of the implementation of an amplifier-based MOS analog neuron capable of performing these tasks and also the optimization of the synaptic weights using in-loop circuit simulations. MOS transistors operating in the triode region are used as variable resistors to convert the input and weight voltage to a proportional input current. To test the analog neuron in full networks, an automatic generator is developed to produce a netlist based on the number of neurons on each layer, inputs and weights. Simulation results using a CMOS 180 nm technology demonstrate the neuron proper transfer function and its functionality while trained in test datasets.