Extending Magnetoresistive AC Transfer Characteristics for Current Measurement

This paper presents an open-loop compensation method in order to improve a commercial current sensor, based on the anisotropic magnetoresistive effect, for applications requiring high bandwidth current measurement. A simple passive differential filter is proposed to extend the open-loop AC transfer characteristic of AMR sensor. The sensitivity and bandwidth of the overall system are discussed by a transfer function analysis. Instrumentation setup and hardware prototype has been developed, and significant test results are shown.