Semiconductor device including differential input circuit and calibration method thereof

A calibration method of a differential input circuit for outputting an output signal by receiving first and second input signals respectively inputted to first and second input transistors, the calibration method comprising:

• entering a calibration mode;
• generating a first judge signal by comparing the output signal with a first comparison voltage, and generating a second judge signal by comparing the output signal with a second comparison voltage;
• performing iterations each comprising:
• performing iterations of adjusting fine codes according to the first and second judge signals and adjusting a drivability of each of the first and second input transistors by a second strength according to the adjusted fine codes;
• and
• adjusting, when any of the adjusted fine codes reaches a maximum count value, coarse codes according to the first and second judge signals and adjusting the drivability of each of the first and second input transistors by a first strength greater than the second strength according to the adjusted coarse codes.

A calibrator for calibrating a circuit configured to amplify differential inputs respectively through first and second transistors to generate an output, the calibrator comprising:

• a voltage circuitry suitable for generating a target voltage range and a reference voltage provided as each of the differential inputs;
• and
• a control circuitry suitable for adjusting, when the output is beyond the target voltage range, each drivability of the first and second transistors to cause the circuit to change the output,
• wherein the control circuitry comprises a coarse adjuster circuit and a fine adjuster circuit connected together to one of the first and second transistors, and
• the control circuitry adjusts the drivability through iterations each comprising iterations of fine adjustments made by the fine adjuster circuit and a coarse adjustment made by the coarse adjuster circuit to be performed when the fine adjustment of a current iteration reaches a fine adjustment limit.