TPS84320's application

I have some questions about TPS84320 ,i can not sure.

For the simple use the chip of TPS84320 , according to the datasheet about TPS84320, i can float these pins as followed :"INH/UVLO","SS/TR","PWRGD" ,can i ?

 But how can i deal with the pins of "PH" ? The pin is described that "Phase switch node.These pins should be connected to a small copper island under the device for

thermal relief.Do not place any external component on this pin or tie it to a pin of another function.".Can i float it or connect it to the GND ? Followed is the schematic:

Is it right ?