Hall-type transducing device

A silicon integrated circuit chip comprising a semiconductor substrate of one conductivity type, an epitaxial layer of the opposite conductivity type superposed on said substrate, two matched Hall elements in said epitaxial layer immediately adjacent to each other, one of said Hall elements serving as a sensor and being connected to amplifier circuit means which amplifies the output voltage thereof, voltage regulator means connected to said sensing Hall element and said amplifier circuit means for applying a regulated supply voltage thereto, said voltage regulator means including the other of said Hall elements, and a current-regulating circuit responsive to changes in resistance of said other Hall element due to changes in ambient temperature for providing current at a level that substantially maintains the biasing current required by said sensing Hall element as its resistance changes due to the same ambient temperature changes.

A magnetic sensing device comprising an integrated circuit transducing means responsive to two different strengths of an applied magnetic field for changing state between operate and release conditions, respectively, and for producing two signals representative thereof, a permanent magnet operatively associated with said transducing means for movement between first and second positions relative to said transducing means at which said fields of two different strengths, respectively, are applied to said transducing means, said transducing means being in operate state when said magnet is in said first position and in release state when said magnet is in said second position, both said magnet and said transducing means having temperature coefficients which substantially track at the operate state of said transducing means and the first position of said magnet for changes in ambient temperature within a predetermined range of temperatures.

A Hall-type transducing device comprising an integrated circuit responsive to two different strengths of an applied magnetic field for changing state between operate and release conditions and for producing two signals, respectively, representative thereof, magnet means for selectively applying a variable strength magnetic field including said two different strengths to said integrated circuit, said integrated circuit having a sensitivity for said operate condition that varies with changes in ambient temperature, said magnet means having a temperature coefficient whereby the field produced thereby varies with changes in ambient temperature, said sensitivity of said integrated circuit varying with temperature according to a relations that causes a change of state of said transducing means to said operate condition at all ambient temperatures within a predetermined range of temperatures, said sensitivity further tracking said field strength at substantially the same rate of change for variations in said ambient temperature.

A magnet having at least one magnetic pole, transducing means for generating an electrical signal in response to a magnetic field of predetermined strength, said magnet being movable relative to said transducing means for juxtaposing said pole a given distance from said transducing means at which said predetermined strength field is applied to said transducing means, both said magnet and said transducing means having temperature coefficients which substantially track over a given range of temperatures such that said transducing means always generates said signal for different temperatures within said range when said magnet pole is said given distance therefrom.