The present disclosure concerns a voltage regulation circuit formed inside and on top of a monolithic semiconductor substrate having a surface covered with a gallium nitride layer, comprising: between a first terminal and a second terminal, a first resistor and a first d-mode type HEMT transistor; and between the first terminal and the third terminal, a second d-mode type HEMT transistor; wherein the midpoint between the first resistor and the first transistor is coupled to the gates of the first and second transistors.