DS90C031B: Input pin un-used

Part Number: DS90C031B

Tool/software:

Hi All,

I have a question about the DS90C031B.

It says that if the input pin is unused, the fail-safe function will guarantee operation even if it is left floating, but is it okay to leave it open?

Do I need to pull it up or down to GND or the power supply?

Best Regards,
Ishiwata