Seoul National University

Pusan National University

ByungGook Park

Hyungjin Kim

Yoon Soo Kim

Jeong-Jun Lee

Disclosed is a neuron circuit in which an overflow signal before fire is retained after the fire. The neuron circuit according to an embodiment of the inventive concept includes a synapse element, a synaptic integration unit and a pulse generation unit. The synapse element receives output signals of a pre-neuron circuit and a post-neuron circuit. The synaptic integration unit includes a capacitor charged by the current flowing into the synapse element depending on the output signals of the pre-neuron circuit and the post-neuron circuit. The pulse generation unit generates an output pulse from the charging voltage of the capacitor. The pulse generation unit includes a pulse generation circuit generating the output pulse depending on the charging voltage of the capacitor and an overflow signal retaining unit connected between the capacitor and the pulse generation circuit and retaining an overflow signal, which exceeds a threshold voltage among the charging voltage of the capacitor after the pulse generation unit fires.

Neuron circuit

A neuromorphic system and a memory device are provided. The neuromorphic system includes input neurons that provide input signals, output neurons that provide output signals, and a plurality of synapse units provided at interconnecting points between the input neurons and the output neurons. Each of the synapse units has a structure in which a plurality of synapse elements are connected in parallel to each other between one input neuron among the input neurons and one output neuron among the output neurons. Both of a multi-level operation and information retention are satisfied. The weight of a synapse unit is gradually and symmetrically changed. The synapse elements are stacked in a 3D stack structure, thereby increasing the number of levels, which is able to be implemented, and thereby representing a high degree of integration.

Growing community of inventors

Seoul, South Korea

ByungGook Park