Driver for normally on III-nitride transistors to get normally-off functionality

A semiconductor device, comprising:

• a depletion mode GaN FET;
• an integrated driver/cascode transistor IC having an upper cascode I/O port, a lower cascode I/O port, a gate I/O port, a Vss port, a VDD port, a Vcc port, and further including:
• a cascoded NMOS transistor in a silicon substrate, the cascoded NMOS transistor having a drain connected to the upper cascade I/O port and a source connected to the lower cascode I/O port;
• and
• a driver circuit in said silicon substrate, so that a gate node of said cascoded NMOS transistor is connected to said driver circuit, wherein the driver circuit includes:
• an edge detector circuit connected to the gate I/O port;
• a level shifter circuit connected to the edge detector circuit;
• and
• a driver buffer connected between the level shifter circuit and the cascoded NMOS transistor;
• an electrical connection between a drain node of said GaN FET and a drain terminal of said semiconductor device;
• an electrical connection between a source node of said GaN FET and the upper cascode I/O port;
• an electrical connection between a gate node of the GaN FET and the lower cascode I/O port;
• an electrical connection between the gate I/O port and a gate terminal of the semiconductor device;
• and
• an electrical connection between the Vss port and a Vss terminal of the semiconductor device.