Patent attributes
In a self refresh period control circuit for controlling a refresh period of a semiconductor memory device in response to operating temperature of the device, a temperature sensor part generates a first period control signal in response to a self refresh start signal or self refresh completion signal, senses operating temperature of the semiconductor memory device in response to a clock signal generated by the self refresh start signal, and generates a corresponding second period control signal. A period magnification control part controls a self refresh period in response to the first and second period control signals. Accordingly, a refresh period characteristic change based on operating temperature, which is causable by an initial self refresh, is implemented.
