Signal amplifying circuit for magnetoresistive element

摘要

A signal amplifying circuit has a differential amplifying circuit, a capacitor and a voltage follower. This circuit takes as input signal the signals outputted from the two terminals of an MR element to which a bias electric current is supplied, and amplifies and outputs the difference in input signals from output terminals. One input terminal of this circuit is connected directly with one of the terminals of the MR element. A capacitor connects the other input terminal of this circuit with the another terminal of the MR element. The two input terminals of this circuit are connected respectively with a non-inverting input terminal and an inverting input terminal of the voltage follower. The voltage follower provides an output to an input terminal of this circuit via a resistance.