A circuit device includes first and second output signal lines from which first and second output signals constituting differential output signals are output, and first to n-th output drivers coupled to the first and second output signal lines. In a first mode, i number of output drivers of the first to n-th output drivers drive the first and second output signal lines based on first and second input signals constituting differential input signals. In a second mode, j number of output drivers of the first to n-th output drivers drive the first and second output signal lines based on the first and second input signals.