Patent ID: 7440227

Claim:
A magnetic head having a Hall effect sensor comprising: a generally planar body made of a semiconductor heterostructure; a first contact comprising a first drain formed over a first end of the body; a second contact comprising a second drain formed over the first end of the body; the first and the second contacts being spaced equally apart from a centerline of the body; a third contact comprising a source formed over a second end of the body which is opposite the first end of the body; the Hall effect sensor being carried by the magnetic head at an air bearing surface (ABS), such that the body is exposed to magnetic field signals substantially normal thereto from magnetic recording media which has a plurality of recorded bits with at least one of a first bit polarity and a second bit polarity; a first resistor coupled between a reference voltage and the first contact; a second resistor coupled between the reference voltage and the second contact; a current source coupled to the third contact and adapted to produce a current 2 I through the body, such that the first drain has a first current I 1 =I−i and the second drain has a second current I 2 =I+i, where i is a differential current which varies based on whether the magnetic field signals correspond to a recorded bit having the first bit polarity or the second bit polarity; and a voltage output taken between the first and the second contacts and providing a differential voltage which varies based on whether the magnetic field signals correspond to a recorded bit having the first bit polarity or the second bit polarity.