Differential magneto-resistive head pre-amplifiers for single polarity power supply applications

摘要

Magneto-resistive (MR) head pre-amplifiers for single polarity power supply applications are presented. An exemplary pre-amplifier includes a bias network coupled to first and second input terminals of the pre-amplifier, the input terminals for receiving signals corresponding to variations in magnetic fields from an MR head. At least one gain stage having first and second input terminals and first and second output terminals for amplifying the received signals is included. A pair of coupling capacitors, each capacitor being connected between a respective input terminal of the pre-amplifier and a corresponding respective input terminal of the at least one gain stage, are further included in the pre-amplifier design. Finally, the exemplary pre-amplifier includes a pair of feedback capacitors, each capacitor being connected between respective input and output terminals of the at least one gain stage. The pre-amplifier is powered by a single polarity power supply.