AG920-07E NVE, AG920-07E Datasheet - Page 127

• Manufacturer Part Number: AG920-07E
• Description: KIT EVALUATION GT SENSOR
• Manufacturer: NVE

Specifications of AG920-07E

• Sensor Type: Magnetic. GMR (Giant Magnetoresistive)
• Interface: Analog
• Embedded: No
• Utilized Ic / Part: ABL & AKL Series GT Sensors
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Supply: -
• Sensitivity: -
• Sensing Range: -
• Other names: 391-1063

flux concentrator’s length to the gap between the two flux concentrators. The long dimension of the
flux concentrators should be aligned with the sensitive axis of the NVE sensor. To minimize the gap,
the flux concentrators should butt up against the NVE sensor package.
Since the effective permeability of the flux concentrators is equal to the concentration factor, material
with permeability 100 or more times the concentration factor, will be more than sufficient. Hot rolled
iron wire or even cut off iron nails will work. Flux concentrators can be round or rectangular in cross
section for mounting considerations. The NVE sensor must be centered within the flux concentrators’
cross sectional area. The diameter of the flux concentrators should be an appreciable fraction of the
gap length or flux spreading in the gap will reduce the concentration factor. The flux concentration
achieved will depend on all dimensions. However, it will depend primarily on the ratio of the
concentrator length to gap. The best calculation, however, is an experimental measurement made with
an actual sensor and flux concentrators. For prototyping and production, the external flux concentrator
can be placed down on the PCB or other substrate. The top of the metal strip must be at least as high as
the sensor package to be truly effective.
It should be noted that a flux concentrator that increases the sensitivity of a GMR sensor by a factor of
five will also reduce the maximum field to which the sensor can respond to one-fifth its original value.
Currency Detection and Validation
Currency detection and validation is a very important application of magnetic media detection. NVE’s
sensors have been used for detecting the magnetic material in paper bills. This magnetic material can
be modeled as very small bar magnets. The magnetic field emitted by the bar magnets has two
detectable orientations. The first is the vertical (radial) component of the field, and second is the
horizontal (axial) component of the field. The sensitive axis of the sensor should be parallel with the
component of field desired, i.e., the horizontal axis, to pickup the horizontal component of the field.
Component
Vertical
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Application Notes
Horizontal
Component