Original Publication Date: 1984-Jun-01
Included in the Prior Art Database: 2005-Feb-04
Magnetoresistive (MR) heads are DC biased sensors in which the resistance of a magnetoresistive element varies as a function of the applied magnetic field. The actual resistance variations due to the applied magnetic field are much smaller than the bulk resistance of the element. Over the life of the head, this bulk resistance can increase to five times its original value due to wear and cause undesirable tradeoffs in biasing methods because the power dissipation and current density ratings of the element must not be violated. In the past, the element was biased at a constant voltage over time and as the bulk resistance of the element increased, the bias current reduced linearly, thus reducing the power dissipation of the sensor over time.