8.3.4 Fail-Safe Logic

The TMUX1247 supports Fail-Safe Logic on the control input pin (SEL) allowing for operation up to 5.5 V, regardless of the state of the supply pin. This feature allows voltages on the control pin to be applied before the supply pin, protecting the device from potential damage. Fail-Safe Logic minimizes system complexity by removing the need for power supply sequencing on the logic control pins. For example, the Fail-Safe Logic feature allows the select pin of the TMUX1247 to be ramped to 5.5 V while V_DD = 0 V. Additionally, the feature enables operation of the TMUX1247 with V_DD = 1.2 V while allowing the select pin to interface with a logic level of another device up to 5.5 V.