Patent ID: 8129815

Claim:
A high-voltage device comprising: a substrate of a first conductivity type; a well region of a second conductivity type disposed in the substrate; second and third regions of the second conductivity type disposed in the well region, the second and third regions being separated by a first area of the well region; one or more first buried regions of the first conductivity type disposed within the first area of the well region that define conduction channels in the first area of the well region, the one or more first buried regions being spaced-apart from the second and third regions; one or more second buried regions of the first conductivity type disposed within a second area of the well region, a third area of the well region separating the one or more second buried regions from the second region; a dielectric layer formed over the first and second buried regions; a layer of resistive material formed over the dielectric layer directly above the third area, the layer of resistive material having first and second ends; first and second terminals electrically connected to the first and second ends, respectively, of the layer of resistive material, the second terminal also being electrically connected to the second region; a third terminal electrically connected to the third region; a fourth terminal electrically connected to the substrate and to the one or more first and second buried regions, wherein a voltage provided at the third terminal is substantially proportional to a voltage difference between the first and fourth terminals when the voltage difference is less than a pinch-off voltage of the high-voltage device, the voltage provided at the third terminal being substantially constant when the voltage difference is greater than the pinch-off voltage, the layer of resistive material floating at a potential substantially equal to the voltage difference when the voltage difference is greater than the pinch-off voltage.