Buffer circuit for compensating for a mismatch between on-die termination resistors and semiconductor device including the same, and operating method thereof

A buffer circuit comprising:

• a driver circuit including a plurality of resistors, wherein the driver circuit connects first resistors of the plurality of resistors to a signal transmission path according to a control code, and the plurality of resistors includes at least two different types of resistors in terms of resistance change characteristics;
• a dummy circuit including a dummy resistor selectively connected to the signal transmission path, according to a dummy selection signal, to compensate for a mismatch in the resistance change characteristics between the at least two different types of resistors,
• wherein the dummy resistor of the dummy circuit has the same type of resistance change characteristics as one of the at least two different types of resistors;
• a control unit comprising:
• a resistance change detecting circuit configured to detect the mismatch by detecting resistance changes in the at least two different types of resistors;
• and
• a dummy circuit selecting unit configured to output the dummy selection signal for selecting the dummy resistor of the dummy circuit according to the detection result of the resistance changes in the at least two different types of resistors.

A method for operating a semiconductor device, wherein the semiconductor device includes a buffer circuit having a driver circuit and a dummy circuit, and the driver circuit includes a plurality of resistors having at least two different types of resistors in terms of resistance change characteristics, comprising:

• generating a control code for selecting one or more resistors among the plurality of resistors to be connected to a signal transmission path;
• receiving the control code and a detection signal corresponding to a match in the resistance change characteristics between the at least two different types of resistors;
• generating a dummy selection signal based on the received control code;
• selectively connecting a dummy resistor of the dummy circuit to the signal transmission path based on the dummy selection signal;
• detecting a mismatch by detecting resistance changes in the at least two different types of resistors;
• and
• outputting the dummy selection signal for selecting the dummy resistor of the dummy circuit according to the detection result of the resistance changes in the at least two different types of resistors,
• wherein the at least two different types of resistors includes first-type resistors having a first type of resistance change characteristics and second-type resistors having a second type of resistance change characteristics different from the first type of resistance change characteristics.