Magnetic-field sensor with split-drain MOSFETS

A sensor for a magnetic field comprising:

• an array of split-drain transistors responsive to a magnetic field all connected in parallel, and each split-drain transistor having a first, a second, and a third drain electrode;
• a first reference current generating transistor having a gate electrode;
• a biasing circuit coupled to the gate electrodes of said split-drain transistors and said gate electrode of said first reference current generating transistor in order to bias said split-drain transistors in the saturated state, and in order to actuate said first reference current generating transistor to generate a first reference current;
• a first, a second, and a third current mirror, all mirrors adapted to be controlled by a reference voltage, said second current mirror being coupled to said second drain electrodes of said split-drain transistors to keep said reference voltage at a reference level, said first current mirror being coupled to said first drain electrodes of said split-drain transistors to generate a first sensed current, and said third current mirror being coupled to said third drain electrodes of said split-drain transistors to generate a second sensed current;
• and
• a second reference current generating transistor with its gate electrode adapted to be controlled by said reference voltage to generate a second reference current;
• whereby, said first and second sensed currents, and said first and second reference currents, can be utilized to indicate the strength of said magnetic field.