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10 Spintronics Applications
Unlimited Life—Opto-couplers have limited life time, which degrade over time.
On the contrary, spintronics couplers have unlimited life time that last for an indefinite
period without any degradation of its performance over time.
Similar to opto-couplers, spintronics couplers have a current-mode input since
the electronic signal is applied directly to the coil. Such devices can be driven by any
input voltages up to 400 V, applied across a current-limiting resistor.
On the other hand, dissimilar to opto-couplers that typically need at least two volts
for the light-emitting diode to turn on, in case of spintronics couplers, the coil-drive
input requires only just millivolts. This, in turn, leads to typically less requirement
of drive current.
Some Other Applications
• Conditioning Circuits: Presently, research activities are also being carried out
concerning the electronics required for biasing and conditioning of GMR-based
sensors. In case of GMR sensors, both applied magnetic field and appropriate
circuitry can decide the accurate bias point of the sensor.
• Space Applications: Spanish National Institute of Aerospace Technology (INTA)
is presently carrying out research in the direction of introducing a miniaturized
three axis GMR sensor to the altitude controlling system.
10.6.3 Some Magnetic Tunnel Junction-Based TMR Sensor
Applications
• Sensors based on magnetic tunnel junctions, i.e., tunnel-magnetoresistance
(TMR) sensors can be used in cars’ steering columns to improve the accuracy
of automated parking capabilities. As such, these advances move the automotive industry closer to required instantaneous processing and actions for fully
autonomous driving.
• Various electronic companies have developed TMR sensors. There is ongoing
mass production of TMR sensors since 2014. It is indeed mentioned worthy
that TMR sensors achieve an impressively high output. For instance, about 20
times higher than conventional anisotropic magnetoresistance (AMR) sensors,
and nearly 6 times higher than giant magnetoresistance (GMR) sensors.
• Additional advantages of TMR sensors include high accuracy, high stability
with less temperature drift and less aging deterioration. These sensors are well
employed as angle sensors, position sensors and rotary sensors.
• A very simplified description of the TMR sensor acting as angle sensor is presented
here: When a magnet is rotated on top of a TMR sensor, the orientation of magnetization of its free ferromagnetic layer follows the direction of this rotating magnetic
field. Since the resistance value of the TMR sensor is proportional to the relative
angle of the magnetization directions of its fixed and the free ferromagnetic layer,
10 Spintronics Applications
Unlimited Life—Opto-couplers have limited life time, which degrade over time.
On the contrary, spintronics couplers have unlimited life time that last for an indefinite
period without any degradation of its performance over time.
Similar to opto-couplers, spintronics couplers have a current-mode input since
the electronic signal is applied directly to the coil. Such devices can be driven by any
input voltages up to 400 V, applied across a current-limiting resistor.
On the other hand, dissimilar to opto-couplers that typically need at least two volts
for the light-emitting diode to turn on, in case of spintronics couplers, the coil-drive
input requires only just millivolts. This, in turn, leads to typically less requirement
of drive current.
Some Other Applications
• Conditioning Circuits: Presently, research activities are also being carried out
concerning the electronics required for biasing and conditioning of GMR-based
sensors. In case of GMR sensors, both applied magnetic field and appropriate
circuitry can decide the accurate bias point of the sensor.
• Space Applications: Spanish National Institute of Aerospace Technology (INTA)
is presently carrying out research in the direction of introducing a miniaturized
three axis GMR sensor to the altitude controlling system.
10.6.3 Some Magnetic Tunnel Junction-Based TMR Sensor
Applications
• Sensors based on magnetic tunnel junctions, i.e., tunnel-magnetoresistance
(TMR) sensors can be used in cars’ steering columns to improve the accuracy
of automated parking capabilities. As such, these advances move the automotive industry closer to required instantaneous processing and actions for fully
autonomous driving.
• Various electronic companies have developed TMR sensors. There is ongoing
mass production of TMR sensors since 2014. It is indeed mentioned worthy
that TMR sensors achieve an impressively high output. For instance, about 20
times higher than conventional anisotropic magnetoresistance (AMR) sensors,
and nearly 6 times higher than giant magnetoresistance (GMR) sensors.
• Additional advantages of TMR sensors include high accuracy, high stability
with less temperature drift and less aging deterioration. These sensors are well
employed as angle sensors, position sensors and rotary sensors.
• A very simplified description of the TMR sensor acting as angle sensor is presented
here: When a magnet is rotated on top of a TMR sensor, the orientation of magnetization of its free ferromagnetic layer follows the direction of this rotating magnetic
field. Since the resistance value of the TMR sensor is proportional to the relative
angle of the magnetization directions of its fixed and the free ferromagnetic layer,