Method and circuitry to provide true voltage bias to a magnetoresistive head

摘要

The present invention is directed to a circuit and method for nullifying a drop in the voltage across an MR head caused a parasitic cable resistance. The invention uses local modeling of the cable resistance in order to generate a nulling voltage, equal in magnitude to the voltage across the cable resistance. The magnitude of the nulling voltage is adjusted as the resistance of the MR head varies within a population of heads. The nulling voltage is added to the bias voltage, in order to negate the effect of the cable resistance.