SN65HVD72: Flow while Vcc is off

Hi Goto,

The device was characterized at Vcc = 0V, and DE = 0 V, with Vi = +12V and Vi = -7V (the min / max range of recommended operation for Vi) to realize the expected bus input current for a disabled driver. Vi is the input voltage at any bus terminal (separate or common mode). The specs in the datasheet show that 75 uA (+12V) and -40 uA (-7 V) should be expected.

The leakage current must be considered when calculating the maximum number of nodes of an RS-485 bus. See page 2 of this application for reference on this: RS-485 basics: how to calculate unit loads and the maximum number of nodes on your (ti.com). 

Regards, Amy