SN65LVDM179 unused in/output pin

All of this family (LVDM179, LVDM180, LVDM050, LVDM051, LVDS179, LVDS180, LVDS050, LVDS051) are Open-Circuit Fail Safe for the LVDM/S differential receiver input. 

This means the the inputs do not need any external components to operate correctly and there are no issues when left open.

Ken.

Ken,

I wants to know more about driver input and output and receiver output as well.

The specification (http://focus.ti.com/lit/ds/symlink/sn65lvdm179.pdf) for the LVDM179 does a good job explaining the open-circuit fail safe mechanism for the receiver.  The transmitter would simply disable the driver.

Ken,

179 driver has no pin to disable the driver. My question is how to treat unused in/out pin of receiver and driver…

If receiver input has open, the output has H and if driver input has open, the driver output has “L” for Y and “H” for Z output.

I’m wondering they need pull-down/up at unused receiver and driver’s in/output pins or not?...Samsung is concerning about any noise/radiation on unused pins.

I would put a place holder for a pull-down on the input of the "D" (driver) as a precaution, but in looking at the structure in the spec, it looks as though it has a weak pull-down