Patent ID: 9625534
Date: 2017-04-18
CPC Classifications: G01R

Claim:
1. An electronic circuit comprising: a first magnetic field detection circuit that produces a first signal indicating a strength of a magnetic field; a second magnetic field detection circuit that selectively receives a power signal and produces a second signal indicating the strength of the magnetic field, wherein the second signal provides a more accurate indication of the strength of the magnetic field than the first signal; and a control circuit configured to determine whether the first signal indicates a change greater than a predetermined amount in the strength of the magnetic field and to couple the power signal to the second magnetic field detection circuit in response to a determination that the strength of the magnetic field has changed by greater than the predetermined amount; an output circuit that provides, as an output of the electronic circuit, an output signal that is based only on the second signal produced by the second magnetic field detection circuit while the second magnetic field detection circuit is receiving power.