If the input terminal (for the control circuit) and the input/output terminal (I/O terminal) have a tolerant function and the IOFF characteristic of the DC characteristic is specified, the power of bus switch can be turn off while the signal on.
How to check the tolerant function of the input/output terminals (I/O terminals) of the bus switch
If the input voltage (VIN) and switch input/output voltage (VS) (Measurement condition : VCC = 0 V or switch = OFF) do not depend on the power supply voltage within the operating range of the data sheet, the device has tolerant function
Please refer to the operating range of TC7MBL3257CFT (Table-1). Both are independent of the power supply voltage and are 0 to 3.6 V, so you can see that they have a tolerant function.
Table-1 TC7MBL3257CFT Operating Ranges
Also, please check whether there is a specification for power off leakage current (IOFF) in the DC characteristics. Please refer to the DC characteristics of the TC7MBL3257CFT. There is a specification for the power off leakage current (IOFF), which is only 40 μA leakage.
Table-2 TC7MBL3257CFT DC characteristics
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