Gallium nitride regulator circuits and methods of operating the same

A circuit comprising:

• a first circuit having a negative temperature coefficient and including a plurality of impedance elements;
• and
• a second circuit having a positive temperature coefficient and including a first GaN-based transistor and a second GaN-based transistor and the plurality of impedance elements, the second circuit operatively coupled to the first circuit;
• a first gallium nitride (GaN)-based transistor having a first gate terminal, a first source terminal and a first drain terminal;
• a second GaN-based transistor having a second gate terminal, a second source terminal and a second drain terminal, the second gate terminal coupled to the first drain terminal;
• a plurality of impedance elements including a first impedance element and a second impedance element, the first source terminal coupled to a ground through the first impedance element and the second impedance element;
• an input terminal coupled to the first gate terminal of the first GaN-based transistor;
• and
• an output terminal coupled to the second source terminal of the second GaN-based transistor;
• wherein an output voltage at the output terminal tracks an input voltage at the input terminal;
• wherein a voltage term dependent on a gate-source voltage of the first GaN-based transistor and a gate-source voltage of the second GaN-based transistor has a positive temperature coefficient and a voltage term dependent on the first impedance element has a negative temperature coefficient, the positive temperature coefficient and the negative temperature coefficient arranged to substantially cancel;
• and
• wherein a first the first impedance element of the plurality of impedance elements is directly coupled to the second impedance element of the plurality of impedance elements.

A circuit comprising:

• a first gallium nitride (GaN)-based transistor having a first gate terminal, a first source terminal and a first drain terminal;
• a second GaN-based transistor having a second gate terminal, a second source terminal and a second drain terminal, the second source terminal coupled to the first source terminal;
• an input terminal coupled to the first gate terminal and arranged to receive a first voltage;
• an output terminal coupled to the second gate terminal;
• and
• a power supply terminal coupled to the first drain terminal and the second drain terminal;
• wherein the first source terminal is coupled to a ground through a first impedance element, the first impedance element having a zero temperature coefficient, and
• wherein the circuit is arranged to generate an output voltage at the output terminal that tracks the first voltage.