Fault-protected dual 2:1 multiplexer with latch-up immunity and 1.8V logic

The Texas Instruments TMUX7436F is a CMOS analog multiplexer with latch-up immunity in a dual channel, 2:1 configuration. The device functions well with dual supplies (±5V to ±22V), a single supply (8V to 44V), or asymmetric supplies (such as VDD = 12V, VSS = –5 V). The overvoltage protection is offered in powered and powered-off conditions, making the device ideal for applications where power supply sequencing may not be precisely controlled.

The device blocks fault voltages up to +60V or −60V relative to ground in powered and powered-off conditions. When no power supplies are present, the switch channels stay in the OFF state regardless of switch input conditions, and any control signal present on the logic pins is ignored. If the signal path input voltage on any Sx pin surpasses the supply voltage (VDD or VSS) by a threshold voltage (VT), then the channel turns OFF, and the Sx pin becomes high impedance. Depending on the DR control logic, the drain pin (Dx) is either drawn to the fault supply voltage that was exceeded or left floating. The device provides two active-low interrupt flags (FF and SF) to give details of the fault and support system diagnostics. The FF flag indicates if any of the source inputs are encountering a fault condition, while the SF flag decodes which specific inputs are encountering a fault condition.