Smart refresh device

The present invention relates to a smart refresh device and to a technology capable of improving a refresh characteristic by performing a smart refresh after detecting a repair address. The smart refresh device of the present invention comprises: an address control unit to determine whether a specific row address is a row hammer address, to store the same, and to perform an addition and subtraction calculation of an address by reversing a first row hammer address; a repair control unit to determine whether the row hammer address is a repaired address if a refresh signal is activated, to store the same, and to output the stored repair address to a second repair control signal if a second smart refresh signal is activated; a repair address storage unit to store an output address of the address control unit if the first smart refresh signal is activated and to output the stored address to a larch address if the second repair control signal; a fuse unit to output a repair signal which shows information regarding the repair address to the repair control unit and to output a decoding signal in response to the latch address; and a calculator to add or subtract the decoding signal in response to adding and subtracting signals if the second repair control signal is activated.