Semiconductor devices having on-die termination structures for reducing current consumption and termination methods performed in the semiconductor devices

A memory module comprising:

• a printed circuit board;
• and
• at least one memory chip mounted on the printed circuit board and comprising at least two stacked semiconductor devices,
• wherein each of the at least two stacked semiconductor devices includes,
• a calibration circuit configured to generate pull-up calibration codes and pull-down calibration codes in response to a reference voltage and a voltage of a calibration terminal, and
• an on-die termination device for controlling a termination resistance of a data input/output pad in response to the pull-up calibration codes, the pull-down calibration codes, and an on-die termination control signal, the termination resistance of the data input/output pad being greater than a resistance of the calibration terminal.

A system comprising:

• a semiconductor device;
• and
• a controller configured to control the semiconductor device via a bus,
• wherein the semiconductor device includes,
• a calibration circuit configured to generate a pull-up calibration code and a pull-down calibration code in response to a reference voltage and a voltage of a calibration terminal, and
• an on-die termination device configured to control a termination resistance of a data input/output pad in response to the pull-up calibration code, the pull-down calibration code, and an on-die termination control signal, the termination resistance of the data input/output pad being greater than a resistance of the calibration terminal.

A termination method performed in a semiconductor device, comprising:

• first adjusting a first termination resistance in response to a pull-up calibration code and a pull-down calibration code;
• and
• second adjusting a second termination resistance in response to the pull-up and pull-down calibration codes and an on-die termination control signal,
• wherein the second termination resistance is greater than the first termination resistance.