A multiplexer includes: a first switch unit coupled between a first input terminal and an output terminal and including a series connection of first and second switches; a second switch unit coupled between a second input terminal and the output terminal; and a third switch unit coupled to a third input terminal and a common node between the first and second switches. Different first and second voltages, and a third voltage greater than one of the first and second voltages and less than the other one of the first and second voltage are applied respectively to the first, second and third input terminals. The multiplexer is operable between a first mode, where the first voltage is transmitted to the output terminal, and a second mode, where the second voltage is transmitted to the output terminal and the third voltage is transmitted to the common node between the first and second switches.