Sensor FAQs
What is GMR?
Giant magnetoresistors,
where resistance changes due to conduction electrons scattering at interfaces.
GMR is an effect of spintronics, which utilizes electron spin rather than electron
charge. The technology is smaller, more sensitive, and lower power than conventional
semiconductors. In awarding the 2007 Nobel Prize in Physics for GMR, the Nobel
Committee said, GMR can be considered one of the first real applications
of the promising field of nanotechnology. This video
has illustrative animations.
What is TMR?
Tunneling Magnetoresistance, which has even
larger signals and lower power than GMR.
Why GMR/TMR sensors?
The advantages of GMR and TMR sensors are summarized with the four Bs: Boxes
(smaller devices); Bits (more sensitive); Batteries (power as low
as nanowatts); and Bullet-proof (extremely reliable).
What types of GMR/TMR sensors does NVE offer?
Analog
Magnetometer Bridge Sensors
Analog
Gradiometer Bridge Sensors
I²C/SPI
Sensors
Magnetic
Switch Sensors
Angle
Sensors
Gear-Tooth
Sensors
Encoder
Sensors
Quadrant
Rotation Sensors
I²C/SPI
Magnetometers
Current
Sensors
What types of smart sensors does NVE offer?
Smart magnetometers,
smart angle sensors, and smart noncontact current sensors. Smart sensors are
available with either SPI or I²C interfaces, and all are in ultraminiature
TDFN packages.
Whats the difference between tesla, gauss, and
oersteds?
Tesla and gauss are units of magnetic flux density. One tesla is 10,000 gauss.
Oersteds are units of field strength. Oersteds and gauss have a one-to-one correspondence
in air.
Whats the difference between a magnetometer and gradiometer?
A magnetometer sensor measures magnetic field strength. A gradiometer measures the magnetic field strength gradient, or change, over a distance.
Whats your most sensitive sensor?
The ALT021-10E has an amazing
sensitivity of 500 mV/V/mT, more than one thousand times better than a typical
Hall-effect sensor.
Whats the sensor minimum supply voltage?
Analog
sensors can run on any voltage because they have no active components. For
digital switch sensors, AHx-Series sensors
operate as low as 0.9 V supply voltage.
What packages are available?
The most popular packages are SOICs, MSOPs, 2.5 mm TDFNs, 1.1 mm ULLGAs, and 0.5
mm WLCSPs.
Whats the smallest package?
We offer sensors in a 0.55 mm wafer-level chip-scale packages.
How far away can your sensors detect a magnet?
More than 20 inches (500 mm) with a strong magnet and sensitive sensor, although
it depends on many factors. Heres a demonstration.
I want to determine the current through a PCB trace.
How can I figure out the magnetic field generated?
You can use Amperes law to estimate the magnetic field generated by current
flowing through a circuit-board trace. Heres a video,
and we have a calculation webapp.
What are NVEs quality certifications?
NVE is certified under ISO9001:2015 and certified conforming with IATF 16949,
First Edition 2016-10-01.
Where can I get magnets for experiments and prototypes?
Popular magnets
are in-stock on NVEs online store, and several sensor evaluation
kits include magnets.
How can I try NVE sensors?
The NVE Online Store has no minimum
order and $9.95 flat-rate shipping within the U.S., and $49.95 outside the U.S.
Sensor Evaluation
Kits are available to try out a variety of parts.