The pendulum-like fluxgate magnetic field sensor (original) (raw)
Related papers
An Integrated Micro-Fluxgate Magnetic Sensor With Front-End Circuitry
IEEE Transactions on Instrumentation and Measurement, 2009
In this paper, a double-axis planar micro-Fluxgate magnetic sensor and its front-end circuitry are presented. The ferromagnetic core material, i.e., the Vitrovac 6025 X, has been deposited on top of the coils with the dc-magnetron sputtering technique, which is a new type of procedure with respect to the existing solutions in the field of Fluxgate sensors. This procedure allows us to obtain a core with the good magnetic properties of an amorphous ferromagnetic material, which is typical of a core with 25-μm thickness, but with a thickness of only 1 μm, which is typical of an electrodeposited core. The micro-Fluxgate has been realized in a 0.5-μm CMOS process using copper metal lines to realize the excitation coil and aluminum metal lines for the sensing coil, whereas the integrated interface circuitry for exciting and reading out the sensor has been realized in a 0.35-μm CMOS technology. Applying a triangular excitation current of 18 mA peak at 100 kHz, the magnetic sensitivity achieved is about 10 LSB/μT [using a 13-bit analog-to-digital converter (ADC)], which is suitable for detecting the Earth's magnetic field (±60 μT), whereas the linearity error is 3% of the full scale. The maximum angle error of the sensor evaluating the Earth magnetic field is 2 • . The power consumption of the sensor is about 13.7 mW. The total power consumption of the system is about 90 mW.
Displacement Sensor Based on Fluxgate Magnetometer
The measurement of distance and position of physical object is very essential for many applications. To measure the change of a very small distance or position, several kinds of sensors can be used such as: LVDT, capacitive, or eddy current.
An Integrated Micro-Fluxgate Magnetic Sensor with Sputtered Ferromagnetic Core
2006
In this paper a double axis planar micro-Fluxgate magnetic sensor is presented. The ferromagnetic core material, the Vitrovac 6025 X, has been deposited on top of the coils with the DC-magnetron sputtering technique, a new type of procedure with respect the existing solutions in the field of Fluxgate sensor. This procedure allows us to obtain a core with the good magnetic properties of the amorphous ferromagnetic material, typical of a core 25 mum thick, but with a thickness of only 1 mum, typical of a core electrodeposited. The micro-Fluxgate has been realized in a 0.5 mum CMOS process using copper metal lines to realize the excitation coil and aluminum metal lines for the sensing coils. Applying a triangular excitation current of 18 mA peak at 100 kHz the magnetic sensitivity achieved is about 0.45 mV/muT, suitable for detecting the Earth's magnetic field (plusmn50 muT), while the linearity error is 1.15% of the full scale. The maximum angle error of the sensor, evaluating the Earth magnetic field, is 3.4deg. The power consumption of the sensor is about 13.7 mW
RTD fluxgate: a low-power nonlinear device to sense weak magnetic fields
IEEE Instrumentation & Measurement Magazine, 2000
luxgate magnetometers have always been of interest to technical and scientific communities to sense weak magnetic fields (in the range of 10 −6 ) with a resolution of 100 pT at room temperature. These devices find applicability in fields such as space, geophysical exploration and mapping, nondestructive testing, and assorted military applications.
Magnetostriction Offset of Fluxgate Sensors
IEEE Transactions on Magnetics, 2015
Magnetostriction is generally believed to cause excessive offset and noise in fluxgate sensors. We show that although the magnetostrictive core tapes are susceptible for offset instability, there is no simple direct mechanism for the generation of the second harmonic signal by magnetostriction. Offset and noise are caused by a variation of local core properties and mechanical stresses together with magnetoelastic coupling.
Design, Fabrication, and Characterization of a 3-D CMOS Fluxgate Magnetometer
IEEE Transactions on Magnetics, 2000
A dual-core 3-D microfluxgate magnetometer fabricated by a simple and inexpensive fabrication process is described in this paper. The microfluxgate is able to operate along a nearly linear -relationship at the second harmonic frequency and features good characteristics of high sensitivity and low noise response. These characteristic results indicate a field-to-voltage transfer coefficient of 11 V/T measured at the second harmonic frequency, power consumption of 67.3 mW, and a field noise response less than 12 nT/ Hz at 1 Hz. In brief, our proposed device not only enhances responsivity capability and linear -characteristics, but also is CMOS process compatible, which is considered both function-efficient and cost-effective.
Fluxgate magnetic sensor and front-end circuitry in an integrated microsystem
Sensors and Actuators A-physical, 2006
A complete vector-2D micro-integrated sensors system for magnetic field measurement is proposed. The system consists of a micro-integrated Fluxgate magnetometer with front-end electronic circuitry based on second-harmonic detection. The magnetic core of the sensor is the VITROVAC 6025X deposited over the micro-integrated coils with the RF magnetron sputtering process deposition.
IEEE Transactions on Instrumentation and Measurement, 2005
In this paper, analytical and experimental results on fluxgate magnetometers, intended to sense dc magnetic field, that make use of a readout technique based on the estimation of the residence times in the stable attractors are presented. The approach, exploiting the inherent nonlinear character of the bistable core dynamics, is based on the time-domain characterization of the transitions between the two saturation states of the hysteresis loop that is inherent in the ferromagnetic core dynamics. This readout technique affords the possibility of low amplitude and frequency reference (or bias) driving signals (sinusoidal or triangular), compared to conventional fluxgates, thereby reducing the device power requirements. The efficacy of this strategy is shown through an analytical approach, and via experimental results that suggest guidelines for the optimal design of the device. Considerations of the effects of a suitable choice of the magnetic core (in terms of its hysteresis behavior) have also been included. Experiments, carried out on miniaturized laboratory fluxgate prototypes with different ferromagnetic materials, reveal good performances of the proposed methodology, including suitable sensitivity and resolution, as well as low cost.
Advances in Magnetic Field Sensors
The most important milestone in the field of magnetic sensors was when AMR sensors started to replace Hall sensors in many applications where the greater sensitivity of AMRs was an advantage. GMR and SDT sensors finally found applications. We also review the development of miniaturization of fluxgate sensors and refer briefly to SQUIDs, resonant sensors, GMIs, and magnetomechanical sensors.