TMUX2889 2:1 (SPDT) 2-Channel Switch Texas Instruments TMUX2889 2:1 (SPDT) 2-Channel Switch is a complementary metal-oxide semiconductor (CMOS) multiplexer with two independently selectable 2:1, single-pole, double-throw (SPDT) switch channels. This device works with a single supply (1.6V to 5.5V) but can pass bidirectional analog and digital signals beyond the supply from -5.5V to 5.5V.