Patent classifications
G01R33/0082
RATIOMETRIC SENSOR CIRCUIT
The present disclosure relates to a sensor circuit including a control circuit configured to control a constant first signal to a ratiometric second signal using a first amplifier adjustable by an actuating signal, and an adjustable second amplifier for a sensor signal, the gain of which is adjustable by the actuating signal.
Magnetic sensor based on wheatstone bridge and manufacturing method thereof
The present invention relates to a magnetic sensor based on a Wheatstone bridge and a manufacturing method thereof. The magnetic sensor according to an embodiment includes a magnetic field sensing unit that is provided with a plurality of magneto resistors forming a resistance bridge, a magneto resistor monitoring unit that monitors resistance values of the plurality of magneto resistors, and an offset adjusting unit that adjusts a resistance value of a thin film variable resistor connected to at least one terminal among a plurality of current terminals provided in the resistance bridge based on the monitoring result of the resistance values.
REDUCING STRAY MAGNETIC-FIELD EFFECTS USING A MAGNETIC-FIELD CLOSED-LOOP SYSTEM
In one aspect, a magnetic-field sensor includes main coil circuitry configured to generate a first magnetic field signal at a first frequency. A reflected signal is generated from a target caused by the first signal generated by the main coil circuitry. The magnetic field sensor also includes magnetoresistance circuitry configured to receive an error signal. The error signal is formed from a combination of the reflected signal and a second magnetic field signal. The magnetic-field sensor further includes analog circuitry configured to receive an output signal from the magnetoresistance circuitry, digital circuitry configured to receive an output signal from the analog circuitry, a mixer configured to receive a feedback signal from one of the digital circuitry or the analog circuitry, and secondary coil circuitry configured to receive a driver signal from the mixer causing the secondary coil circuitry to generate the second magnetic field signal at the first frequency.
Current sensor device
A sensor device includes a silicon substrate having an active surface; a first sensing area disposed near a first edge of the active surface of the silicon substrate such that the first sensing area has at least one first magnetic sensing element is made of a first compound semiconductor material and contact pads; and a second sensing area disposed near a second edge of the active surface of the silicon substrate, such that the second edge is substantially opposite to the first edge, such that the second sensing area has at least one second magnetic sensing element made of a second compound semiconductor material and contact pads. A processing circuit is disposed of in the silicon substrate and is electrically connected via wire bonds and/or a redistribution layer with the contact pads of the first and second sensing areas.
Interface configurations for a wearable sensor unit that includes one or more magnetometers
An exemplary magnetic field measurement system includes a wearable sensor unit that includes a magnetometer and a twisted pair cable interface assembly electrically connected to the magnetometer.
Magnetoresistive element, magnetic sensor, reproducing head, and magnetic recording and reproducing device
The present disclosure provides: a magnetoresistive element having a large magnetoresistance change ratio (MR ratio); and a magnetic sensor, a reproducing head and a magnetic recording and reproducing device. The magnetoresistive element comprises a magnetoresistive film including a pair of body centered cubic (bcc) crystal structure CoFe ferromagnetic layers with a (001) crystal orientation, the pair of layers separated by a non-magnetic layer of Cu with bcc crystal structure.
Reducing voltage non-linearity in a bridge having tunneling magnetoresistance (TMR) elements
In one aspect, a magnetic field sensor includes a plurality of tunneling magnetoresistance (TMR) elements that includes a first TMR element, a second TMR element, a third TMR element and a fourth TMR element. The first and second TMR elements are connected to a voltage source and the third and fourth TMR elements are connected to ground. Each TMR element has a pillar count of more than one pillar and the pillar count is selected to reduce the angle error below 1.0°.
Reducing stray magnetic-field effects using a magnetic-field closed-loop system
In one aspect, a magnetic-field sensor includes main coil circuitry configured to generate a first magnetic field signal at a first frequency. A reflected signal is generated from a target caused by the first signal generated by the main coil circuitry. The magnetic field sensor also includes magnetoresistance circuitry configured to receive an error signal. The error signal is formed from a combination of the reflected signal and a second magnetic field signal. The magnetic-field sensor further includes analog circuitry configured to receive an output signal from the magnetoresistance circuitry, digital circuitry configured to receive an output signal from the analog circuitry, feedback circuitry configured to receive a feedback signal from one of the digital circuitry or the analog circuitry, and secondary coil circuitry configured to receive a driver signal from the feedback circuitry causing the secondary coil circuitry to generate the second magnetic field signal at the first frequency.
Magnetic sensor
A magnetic sensor includes first to fourth resistor sections and a plurality of MR elements. Each of the plurality of MR elements belongs to any of first to fourth groups. The first to fourth groups are defined based on the areas of top surfaces of the MR elements. The first resistor section, the second resistor section, the third resistor section, and the fourth resistor section are constituted of the first group, the second group, the third group, and the fourth group, respectively; the second group, the first group, the fourth group, and the third group, respectively; the first group, the fourth group, the third group, and the second group, respectively; or the third group, the second group, the first group, and the fourth group, respectively.
SENSING MOTOR CURRENT
A circuit for sensing the driving current of a motor, the circuit comprising: a driver configured to generate a driving current for each phase of a multiple-phase motor, the instantaneous sum of all the driving currents being zero; a current sensor for each phase of the multiple-phase motor, each current sensor configured to measure the driving current of that phase and comprising a plurality of current sensor elements arranged with respect to each other such that each current sensor element has the same magnitude of driving current systematic error due to magnetic fields external to the driving current to be measured; and a controller configured to, for each phase of the multiple-phase motor, generate an estimate of the driving current of that phase to be the measured driving current of that phase minus 1/n of the total of the measured driving currents for all phases, n being the number of phases of the multiple-phase motor.