Gain-controllable magnetoresistive analog amplifier

A gain-controllable magnetoresistive analog amplifier, comprising:

• a substrate located in an X-Y plane;
• an output signal magnetoresistive sensor located on the substrate;
• and
• an input signal coil and a gain adjustment coil, the input signal coil and the gain adjustment coil located on two side surfaces of the output signal magnetoresistive sensor, respectively,
• wherein,
• the gain adjustment coil is used to input a gain signal by the generation of a gain magnetic field, in order to set the gain magnetic field is applied along a magnetization direction of a free layer of the output signal magnetoresistive sensor, thereby adjusting the slope of the input resistance-magnetic field transfer curve of the output signal magnetoresistive sensor, and
• the input signal coil is used for inputting a current signal to generate an input magnetic field, in order to apply the input magnetic field to a magnetization direction of a pinned layer of the output signal magnetoresistive sensor, thereby controlling the gain signal to adjust a gain factor of an output signal after the current signal passes through the output signal magnetoresistive sensor, and the current signal is alternate current signal or direct current signal.