Systems and Methods for Detection of Magnetic Fields

摘要

Apparatuses for detecting the strength of magnetic fields may include a first magnetic field detection circuit that produces a first signal indicating a strength of a magnetic field, and a second magnetic field detection circuit that can be turned on and off, and produces a second signal indicating the strength of the magnetic field. A control circuit may be configured to determine whether the first signal indicates a change greater than a predetermined amount in the strength of the magnetic field. If the change is greater than the predetermined amount, the control circuit may turn on the second magnetic field detection circuit. The control circuit may turn off the second magnetic field detection circuit to conserve power if the strength of the magnetic field is relatively stable. Methods for detecting the strength of the magnetic field are also disclosed.