Patent ID: 6710594
Filing Date: 2004-03-23
Classification: G11B,Y10T

Abstract:
A test system determining performance of a merged magnetoresistive read-write head to select a passed read-write head, comprising:a write current source driving a write differential signal pair of said merged magnetoresistive read-write head at a first write current level; a read current source driving a read differential signal pair of said merged magnetoresistive read-write head at a first read current level; a volt meter measuring across said read differential signal pair to create a first voltage reading; means for determining a first Merged Read-write head Resistively as essentially said first voltage reading divided by said first read current level; means for creating a second MRR by control of at least one member of the current source collection comprising said read current source and said write current source; means for calculating a differential MRR as said first MRR minus said second MRR; and means for evaluating said merged magnetoresistive read-write head based upon said differential MRR to create said passed read-write head; and an ESD protection circuit coupled across said read differential signal pair protecting said merged magnetoresistive read-write head from ESD; wherein said means for creating said second MRR is further comprised of at least one member of the collection including the steps of: said write current source driving at a second write current level to create said second MRR; and said read current source driving at a second read current level to create said second MRR; wherein said means for evaluating said merged magnetoresistive read-write head is further comprised of: means for passing said merged magnetoresistive read-write head based upon when said differential MRR is essentially non-positive to select said passed merged read-write head.