Seoul National University

Sung-Tae Lee

Jong-Ho Lee

A synapse string includes first and second cell strings each having a plurality of memory cell elements connected in series and first switch elements connected to first or second ends of the first and second cell strings, respectively. The memory cell elements of the first cell string and the memory cell elements of the second cell string are in a one-to-one correspondence, and a pair of the memory cell elements being in a one-to-one correspondence has terminals to which a read voltage is applied connected to each other to constitute one synapse morphic element, so that the synapse string includes a plurality of synapse morphic elements connected in series. A synapse string array architecture enables forward propagation and backward propagation by implementing high-density synapse strings, so that the synapse string array architecture can be applied to a neural network capable of inferencing and on-chip learning, along with inference and recognition.

Synapse string array architectures for neural networks

Provided is a binary neural network including: a synapse string array in which multiple synapse strings are sequentially connected. The synapse string includes: first and second cell strings, each including memory cell devices connected in series; and switching devices connected to first ends of two-side ends of the first and second cell strings. The memory cell devices of the first and second cell strings are in one-to-on correspondence to each other, and a pair of the memory cell devices being in one-to-on correspondence to each other have one-side terminals electrically connected to each other to constitute one synapse morphic device. A plurality of the pairs of memory cell devices configured with the first and second cell strings constituting each synapse string constitute a plurality of the synapse morphic devices. The synapse morphic devices of each synapse string are electrically connected to the synapse morphic devices of other synapse strings.

Neural network with synapse string array

Provided is synapse strings and synapse string arrays. The synapse string includes: first and second cell strings, each having a plurality of memory cell devices connected in series; and first switch devices, each connected to one of two ends of each of the first and second cell strings. The memory cell devices of the first cell string and the memory cell devices of the second cell string are in one-to-one correspondence to each other, and terminals of pairs of the memory cell devices being in one-to-one correspondence to each other are applied with read voltages and electrically connected to each other to constitute one synapse morphic device, so that the synapse string includes a plurality of synapse morphic devices connected in series. The synapse string includes a peripheral circuit and a reference current source for implementing a function of a neuron.

Growing community of inventors

Gwacheon-si, South Korea

Sung-Tae Lee