SCDS394A March 2021 – October 2021 TMUX7462F
The TMUX7462F conducts equally well from source (Sx) to drain (Dx) or from drain (Dx) to source (Sx). Each signal path has very similar characteristics in both directions; however, it is noted that the overvoltage protection is implemented only on the source (Sx) side. The voltage on the drain is only allowed to swing between VFP and VFN and no overvotlage protection is available on the drain side.
The primary supplies (VDD and VSS) define the on-resistance profile of the switch channel, whereas the fault voltage supplies (VFP and VFN) define the signal range that can be passed through from source to drain of the device. It is good practice to use voltages on VFP and VFN that are lower than VDD and VSS to take advantage of the flat on-resistance region of the device for better input-to-output linearity. The flatest on-resistance region extends from VSS to roughly 3 V below VDD. Once the signal is within 3 V of VDD the on-resistance will expoentially increase and may impact desired signal transmission.