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.