A semiconductor device includes a reference voltage generator configured to output a reference voltage. The reference voltage generator includes a boosting code circuit and a first digital-analog converter (DAC). The boosting code circuit includes a first boosting pulse generator configured to generate a first boosting pulse and a first boosting code controller configured to output a first boosting code based on a reference code and the first boosting pulse. The first DAC is configured to output the reference voltage by converting the first boosting code. The first boosting code has a first code value different from the reference code when the first boosting pulse has a first logic level, and the first boosting code has the same value as the reference code when the first boosting pulse has a second logic level opposite to the first logic level.