Abstract: A connection detector includes: a power supply line for use in supply of a power supply potential; a CC terminal; a ground terminal; an electric-current output circuit arranged between the power supply line and the CC terminal and including a first switch for use in disabling an electric-current output; a pulldown resistor circuit arranged between the CC terminal and the ground terminal and including a second switch for use in disabling a pulldown resistance; a bias circuit configured to generate a first reference potential and a second reference potential that is different from the first reference potential; and a role detector including a first comparator configured to compare the first reference potential with a voltage of the CC terminal and a second comparator configured to compare the second reference potential with a voltage of the CC terminal.

Abstract: A semiconductor device includes a pre-buffer for transferring a data signal on the basis of a first power supply voltage, a main buffer for amplifying and outputting the data signal transferred by the pre-buffer on the basis of a second power supply voltage different from the first power supply voltage, a switch unit for controlling a conductive state between the pre-buffer and the main buffer on the basis of a switch control signal, and a control circuit for generating the switch control signal for controlling the pre-buffer to set an output level of the pre-buffer to ground potential in accordance with transition of logical level of the switch control signal.

Abstract: A semiconductor device includes a pre-buffer for transferring a data signal on the basis of a first power supply voltage, a main buffer for amplifying and outputting the data signal transferred by the pre-buffer on the basis of a second power supply voltage different from the first power supply voltage, a switch unit for controlling a conductive state between the pre-buffer and the main buffer on the basis of a switch control signal, and a control circuit for generating the switch control signal for controlling the pre-buffer to set an output level of the pre-buffer to ground potential in accordance with transition of logical level of the switch control signal.