MEMORY DEVICE FOR OPTIMIZING STATES OF TERMINATIONS ACCORDING TO VARIATIONS OF PROCESS, VOLTAGE, AND TEMPERATURE

摘要

PURPOSE: A memory device for optimizing states of terminations according to variations of a process, a voltage, and temperature is provided to improve an input/output characteristic by optimizing the states of the terminations and receiving external signals. CONSTITUTION: A plurality of terminations(P1 to P5) include variable resistance circuits and pass external signals to operate a memory device. A control circuit(120) generates control signals for controlling resistance values included in the variable resistance circuits in response to a command enable signal for indicating the activation of an auto refresh operation of the memory device and an external enable signal for activating a delay synchronization loop circuit. The delay synchronization loop circuit is in an enabling state after the states of the terminations(P1 to P5) are optimized by the control signals. The states of the terminations(P1 to P5) are optimized by the control signals when the memory device performs periodically an auto refresh operation.