Environmental sensor circuit having a capacitive proximity sensor and magnetic field probe
AssigneeSemtech Corporation
InventorChaouki Rouaissia
Life of this patent
Estimating the term…
Abstract
Environmental sensor circuit for a portable connected wireless device. The circuit includes a capacitive proximity sensor that determines when a user is close to the portable device. The device also has a magnetic field probe that provides a signal that indicates the position of a permanent magnet. The sensor circuit integrates both a digitizing unit and digital signal processing for the suppression of noise and drive in signals coming from the proximity sensor and from the magnetic field probe.
Claims12
An environmental sensor circuit for a portable connected wireless device, the circuit comprising:
- (a) a capacitive proximity sensor configured to determine whether a user is in proximity to the capacitive proximity sensor, by sensing variation in the capacitance of an electrode in electric connection with an environmental integrated circuit, (b) a magnetic field probe, providing a signal proportional to a magnetic field strength, wherein the environmental sensor circuit has an analogue/digital converter configured to produce proximity digital values representative of the capacitance of the electrode and magnetic field digital values representative of the magnetic field strength, the integrated circuit further comprising a digital processor configured for suppressing unwanted noise and drift components from the proximity digital values and from the magnetic field digital values.
An environmental sensor circuit for a portable connected wireless device, the circuit comprising:
- (a) a capacitive proximity sensor configured to determine whether a user is in proximity to the capacitive proximity sensor, by sensing variation in the capacitance of an electrode in electric connection with an environmental integrated circuit, (b) a magnetic field probe, providing a signal proportional to a magnetic field strength, wherein the environmental sensor circuit has an analogue/digital converter configured to produce proximity digital values representative of the capacitance of the electrode and magnetic field digital values representative of the magnetic field strength, the integrated circuit further comprising a digital processor configured for suppressing unwanted noise and drift components from the proximity digital values and from the magnetic field digital values, the environmental sensor circuit further comprising a magnetic field digital output, configured to switch from a logical state to an opposite logical state when the magnetic field sensed by the magnetic field probe exceeds a predetermined threshold.
An environmental sensor circuit for a portable connected wireless device, the circuit comprising:
- (a) a capacitive proximity sensor configured to determine whether a user is in proximity to the capacitive proximity sensor, by sensing variation in the capacitance of an electrode in electric connection with an environmental integrated circuit, (b) a magnetic field probe, providing a signal proportional to a magnetic field strength, wherein the environmental sensor circuit has an analogue/digital converter configured to produce proximity digital values representative of the capacitance of the electrode and magnetic field digital values representative of the magnetic field strength, the integrated circuit further comprising a digital processor configured for suppressing unwanted noise and drift components from the proximity digital values and from the magnetic field digital values, the environmental sensor circuit further comprising a digital bus output for communicating values of proximity and magnetic field to a host system, and/or an interrupt output for requesting the action of a host system when the values of proximity and/or magnetic field meet predetermined conditions.
Dependencies are inferred from the claim text.