摘要 |
Signal isolator circuits using one or more magneto-resistive sensors are disclosed. In a first embodiment, a magneto-resistive sensor is used to sense an input magnetic field. A feedback circuit senses the output signal from the sensor, and applies a current to an output coil that substantially null out the input magnetic field at the magneto-resistive sensor. In another embodiment, the input signal is provided to a first magneto-resistive bridge sensor and an offset input signal is provided to a second magneto-resistive bridge sensor. Changes in sensitivity of the bridge sensors can be detected by comparing the output signal signals from the sensors. The excitation voltage that is applied to the sensors is then adjusted to compensate for any changes in sensitivity. It is contemplated that a single magneto-resistive bridge sensor may be used to effectively perform both measurements of the first and second magneto-resistive bridge sensors.
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