Cascode circuit integration of group III-N and group IV devices

1. An integrated assembly comprising:

a printed circuit board;

a depletion mode III-Nitride transistor die and a group IV transistor die coupled to said printed circuit board;

said depletion mode HI-Nitride transistor die situated on one side of said printed circuit board and said group IV transistor die situated on an opposing side of said printed circuit board;

at least one via in said printed circuit board electrically connecting said depletion mode III-Nitride transistor die to said group IV transistor die;

wherein said group IV transistor die is configured to receive a gate drive signal through a trace situated on said one side of said printed circuit board.

2. The integrated assembly of claim 1 , wherein said depletion mode III-Nitride transistor die is in cascode with said group IV transistor die.

3. The integrated assembly of claim 1 , wherein said depletion mode III-Nitride transistor die is situated over said group IV transistor die.

4. The integrated assembly of claim 1 , wherein said group IV transistor die is directly under and not offset from said depletion mode III-Nitride transistor die.

5. The integrated assembly of claim 1 , wherein said group IV transistor die is offset from said depletion mode III-Nitride transistor die.

6. The integrated assembly of claim 1 , wherein said III-Nitride transistor die comprises a plurality of elongated digits configured for external circuit connection through solder bars.

7. The integrated assembly of claim 1 , wherein said group IV transistor die comprises a passivation layer and solderable contacts exposed through openings in said passivation layer.

8. The integrated assembly of claim 1 , wherein said III-Nitride transistor die comprises a passivation layer and solderable contacts exposed through openings in said passivation layer.

9. The integrated assembly of claim 1 , further comprising a conductive clip coupling a drain of said group IV transistor die to said printed circuit board.

10. The integrated assembly of claim 1 , wherein said group IV transistor die and said depletion mode III-Nitride transistor form an enhancement mode composite device.

11. The integrated assembly of claim 1 , wherein said group IV transistor die includes an enhancement mode transistor.

12. The integrated assembly of claim 1 , wherein at least one of said group IV transistor die and said III-Nitride transistor die are encapsulated on said printed circuit board.

13. The integrated assembly of claim 1 , wherein said III-Nitride transistor die comprises a high-electron-mobility transistor.

14. An integrated assembly comprising:

a printed circuit board;

a power conversion circuit formed on said printed circuit board, said power conversion circuit comprising a depletion mode III-Nitride transistor die and a group IV transistor die coupled to said printed circuit board;

said depletion mode III-Nitride transistor being connected in cascode with said group IV transistor die by said printed circuit board;

wherein said group IV transistor die is configured to receive a gate drive signal through a trace situated on one side of said printed circuit board.

15. The integrated assembly of claim 14 , wherein said power conversion circuit further comprises a control IC situated on said one side of said printed circuit board, said control IC providing said gate drive signal.

16. The integrated assembly of claim 14 , wherein said depletion mode III-Nitride transistor die is situated on said one side of said printed circuit board and said group IV transistor die is situated on an opposing side of said printed circuit board.