Patent ID: 7724460

Claim:
An apparatus for generating at least one signal related to an impedance of a read element in a read channel of a read head, the apparatus comprising: a first circuit, coupled across the read element, configured to provide a first signal from the read element; a second circuit, coupled across a read head circuit portion including the read element and at least one other circuit element connected to the read element, configured to provide a second signal from the read head circuit portion, wherein the at least one other circuit element comprises first and second resistors connected on either side of the read element; a third circuit, coupled to the first and second circuits, configured to generate a combination of the first and second signals as the at least one signal related to the impedance of the read element; and a bias circuit coupled to the read element, the bias circuit configured to apply a biasing signal to the read element, wherein the bias circuit comprises: an amplifier adapted to adjust a gain of the first signal of the read element; a transconductance stage, coupled to the amplifier, adapted to apply a transconductance to the gain adjusted first signal to generate an output bias current; and an integrator adapted to integrate the output bias current of the transconductance stage to provide the biasing signal to the read element.