A terminal circuit and an output stage circuit are provided. The terminal circuit is configured between a transmitter and an external device. The transmitter provides a differential signal to the external circuit. The terminal circuit includes a first to a third switches and a first and a second resistor. The first switch is biased by a first voltage provided by the transmitter. The first and the second resistor receive the differential signal. The second switch is coupled between the first switch and the first resistor. The third switch is coupled between the first switch and the second resistor. The first to the third switches are controlled by a first to a third control signals, respectively. When the transmitter operates in a power-off mode, a voltage level of the first voltage is in ground level, and the first to the third control signals turn off the first to third switches.