Patent ID: 8236656

Claim:
A high-voltage junction field-effect transistor (JFET), comprising: a semiconductor substrate having a first conductivity type; a well region formed in the semiconductor substrate, wherein the well region has a second conductivity type; a first doped region disposed in the well region, wherein the first doped region has the second conductivity type; a second doped region disposed in the semiconductor substrate laterally displaced from the well region, wherein the second doped region has the first conductivity type; a third doped region disposed in the well region laterally displaced between the first and second doped regions, wherein the third doped region has the second conductivity type; a first terminal disposed on the first doped region to electrically couple to the well region; a second terminal disposed on the second doped region to electrically couple to the semiconductor substrate; and a third terminal disposed on the third doped region to electrically coupled to the well region, wherein at least a portion of the well region is configured to be substantially depleted of free charge carriers when a first voltage between the first and second terminals is greater than or equal to a pinch-off voltage, wherein a voltage output at the third terminal is substantially proportional to the first voltage when the first voltage is less than the pinch-off voltage, and wherein the voltage output at the third terminal is substantially fixed and less than the first voltage when the first voltage is greater than or equal to the pinch-off voltage.