Patent ID: 8581649

Claim:
A semiconductor device comprising: a power line; an external terminal; an output driver that is connected to the power line and the external terminal, and outputs an output signal to the external terminal; and a characteristic switching circuit that switches characteristics of the output driver, wherein: the characteristic switching circuit includes a calibration circuit that controls an output impedance of the output driver in an active conduction state of the output driver, and a slew rate control circuit that adjusts a slew rate of the output signal, the slew rate representing an amount of electric potential transition per unit time, the calibration circuit substantially matches an output impedance of the output driver in the active conduction state of the output driver when a first voltage is supplied to the power line with an output impedance of the output driver in the active conduction state of the output driver when a second voltage that is lower than the first voltage is supplied to the power line, when the first voltage is supplied to the power line, the slew rate control circuit sets a rising time and a falling time of the output signal to a first time and a second time, respectively, by relatively increasing the slew rate of the output signal and by setting an amplitude of the output signal to a first amplitude, and when the second voltage is supplied to the power line, the slew rate control circuit sets the rising time and the falling time of the output signal to the first time and the second time, respectively, by relatively decreasing the slew rate of the output signal and by setting an amplitude of the output signal to a second amplitude that is lower than the first amplitude.