Hello ,I am learning the principles of circuit,I only know that its supposed to drive a power amplifier TGA 2590 .
regarding your question two extended schematics photos are attached the node is call VIZ and GIZ and its connected to DB02S2415A component as shown in another picture .
Yes of course the mosfter is opened and closed by the Vgs>Vt condition, however what i have inner logical conflict when on one hand we put "floating" Ground.
But on the other hand we the source is not connected to ground it could be connected to power amplifier and the draing of power amplifier is the load and not plain ground.
So how this virtual ground helps us here?
Thanks.
"Output of UCCxxx should be referenced again Source of MOSFET - this is the way how NOSFET works (it controlled by Gate-Source voltage)"
"BTW - there is no supply attached to isolated side of UCC5304 in schema. I think something was forgotten"
https://www.mouser.co.il/datasheet/2/632/DS_DB02S_D-3106392.pdf