The TMUX4157N is a general purpose 2:1, single-pole double-throw (SPDT), switch that supports a negative supply rail only. The supply voltage can range from -4 V to -12 V and the device supports bidirectional analog and digital signals on the source (Sx) and drain (D) pins ranging from GND to VSS. The state of the select pin (SEL) controls which of the two sources pins are connected to the drain pin. While TMUX4157N supports negative voltages on the supply pin and signal path, the logic input pin is controlled with a positive voltage to allow interfacing with typical control logic circuitry such as a GPIO signal. The logic input pin has 1.8 V logic compatible thresholds and can operate as high as 5.5 for added system flexibility. Fail-Safe Logic circuitry allows voltages on the control pins to be applied before the supply pin, protecting the device from potential damage. Fast transition times and high continuous current through the switch make the TMUX4157N well suited for applications where the system needs to quickly switch between two different voltage inputs. . .