Patent ID: 6731558
Filing Date: 2004-05-04
Classification: G11C

Abstract:
A semiconductor memory device requiring a refresh of storage data, comprising:reference voltage generating circuitry for generating a reference voltage having a temperature dependency; and refresh request generating circuitry having an operating speed determined by the reference voltage generated by said reference voltage generating circuitry, for performing an oscillation operation and issuing a refresh request for requesting said refresh every prescribed number of times of oscillation when activated, wherein said reference voltage generating circuitry includes first and second transistors forming a current mirror stage, a resistance element, having a resistance value having a positive temperature characteristic, interposed between the second transistor and a power supply node, first and second constant current sources coupled to said first and second transistors, respectively, a current supply element connected between a connecting node between said second transistor and the second constant source and said power supply node, and a current/voltage converting circuit, having a driving current determined according to a potential of said connecting node, for generating said reference voltage according to said driving current.