Semiconductor memory device having optimum refresh cycle according to temperature variation

摘要

An apparatus for controlling a refresh cycle in a semiconductor memory device includes a temperature detection controller for generating a detection control signal and a converting control signal; a temperature detection block, which is enabled by the detection control signal, for generating an analog detection voltage in response to a temperature variation; an analog to digital converter, which is enabled by the converting control signal, for converting the analog detection voltage into a digital control code; and a refresh controller for generating a refresh cycle control signal based on the digital control code in order to control the refresh cycle.