Driver circuit and method of operating the same

An integrated circuit (IC) comprising:

• a power supply node;
• a power supply reference node;
• a protection circuit comprising:
• a series of diode-configured enhancement-mode n-type high electron mobility transistors (HEMTs) coupled between the power supply node and the power supply reference node and comprising a voltage tap;
• a first enhancement-mode n-type HEMT comprising a gate coupled to the voltage tap and a source terminal coupled to the power supply reference node;
• and
• a second enhancement-mode n-type HEMT comprising a gate coupled to a drain terminal of the first enhancement-mode n-type HEMT and a source terminal coupled to the power supply reference node;
• and
• a gate driver comprising:
• a third enhancement-mode n-type HEMT comprising a gate coupled to a drain terminal of the second enhancement-mode n-type HEMT;
• a fourth enhancement-mode n-type HEMT coupled between the third enhancement-mode n-type HEMT and the power supply reference node;
• a fifth enhancement-mode n-type HEMT comprising a gate coupled to a source terminal of the third enhancement-mode n-type HEMT and a source terminal coupled to the power supply reference node;
• and
• an output terminal coupled to a drain terminal of the fifth enhancement-mode n-type HEMT.

A method of operating a driver circuit, the method comprising:

• using a series of diode-configured enhancement-mode n-type high electron mobility transistors (HEMTs) to divide a first power supply voltage at a voltage tap;
• receiving the divided first power supply voltage from the voltage tap at a gate of a first enhancement-mode n-type HEMT comprising a source terminal coupled to a power supply reference node;
• receiving a first voltage from a drain terminal of the first enhancement-mode n-type HEMT at a gate of a second enhancement-mode n-type HEMT comprising a source terminal coupled to the power supply reference node;
• receiving a second voltage from a drain terminal of the second enhancement-mode n-type HEMT at a gate of a third enhancement-mode n-type HEMT;
• receiving a third voltage from a source terminal of the third enhancement-mode n-type HEMT at a gate of a fourth enhancement-mode n-type HEMT comprising a source terminal coupled to the power supply reference node;
• and
• generating an output voltage from a drain terminal of the fourth enhancement-mode n-type HEMT at an output terminal.