An integrated high side gate driver structure for driving a power transistor. The structure includes a semiconductor substrate having a first polarity semiconductor material in which a first well diffusion including a second polarity semiconductor material is formed. An outer wall of the first well diffusion is abutted to the substrate. A second well diffusion, having first polarity semiconductor material, is arranged inside the first well diffusion such that an outer wall of the second well diffusion abuts an inner wall of the first well diffusion. The structure includes a gate driver having high side positive and negative supply voltage ports, and a driver input and output. The gate driver includes a transistor driver in the second well diffusion such that control and output terminals of the transistor driver are coupled to the driver input and output, respectively. The structure also includes respective electrical connections between the first and second well diffusions and the negative supply voltage port.