what is the voltage RANGE of Din pin - Xbee XB24-z7wit-004?

what is the voltage RANGE of Din pin - Xbee XB24-z7wit-004?

It is the exact same as VCC. Page 13 of the manual shows the following:

XBee ZB
2.1 - 3.6 V
XBee PRO ZB
3.0 - 3.4 V
XBee SMT
2.7 - 3.6 V