Switch device with input limiting function

A switch device, comprising:

• a switch circuit, comprising a first switch and a second switch, arranged to selectively enable a path between an input terminal and an output terminal, wherein the first switch and the second switch are controlled by a first switch control signal and a second switch control signal, respectively;
• wherein the first switch is a transistor and the second switch is transistor, wherein the two transistors are a same conduction type;
• and
• a switch controller, arranged to refer to a selection signal and a switch signal to respectively generate the first switch control signal at a first switch control signal output terminal, and generate the second switch control signal at a second switch control signal output terminal, wherein when the voltage level of an input signal at the input terminal is larger than a power voltage, the switch controller generates the first switch control signal and the second switch control signal that are capable of turning off the switch circuit;
• and when the voltage level of the input signal is not larger than the power voltage, the switch controller generates the first switch control signal and the second switch control signal according to the switch signal.