A memristor-based neuromorphic engine with a current sensing scheme for artificial neural network applications

By following the big data revolution, neuromorphic computing makes a comeback for its great potential in information processing capability. Despite of many types of architectures reported in conventional CMOS domain, memristor, as an example of emerging devices, demonstrates an intrinsic support of parallel matrix-vector multiplication operation that is widely used in artificial neural network applications. However, its computation accuracy and speed are far from satisfactory, mainly constrained by the features of memristor crossbar array and peripheral circuitry. In this work, we propose a new memristor crossbar based computing engine design by leveraging a current sensing scheme. High parallelism in operation and therefore fast computation can be achieved via simultaneously supplying analog voltages into a memristor crossbar and directly converting the weighted current through a current-to-voltage converter. We implemented and compared the feed-forward neural networks with different array sizes and layer numbers. Our design demonstrates a good computation accuracy, e.g., 96.6% classification accuracy for MNIST handwritten digit in a two-layer design.