AG920-07E NVE, AG920-07E Datasheet - Page 123

• 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

The same analysis was performed on the seven 0.010" wide traces of the same thickness. A voltage of
8.06V was again applied and the resulting graph is shown below in the figure below.
Seven traces were run under the part so that the magnetic fields from the seven traces are additive at
the sensor thus getting a much higher output with less applied current. To a first-order approximation,
theory predicts that the field will be increased seven fold from just a single trace. The sensitivity from
the single trace above is 3.7 mV/V/A; seven times this is 25.9 mV/V/A, which is not quite achieved.
This discrepancy is due to the different current distributions. The loss would not be as extreme if seven
times the current went through the single trace.
Resolution
Resolution is a function of environmental noise. By shielding, amplifying, and filtering, the low limit
and usable resolution can be greatly increased. The data for the analysis done here was with a “raw”
setup, no amplification or filtering. In a zero gauss chamber, single microamps were detected but the
measurement equipment limited any in-depth analysis.
Effects of Biasing
For the analysis done above, a small ceramic magnet was used to supply a magnetic bias field in a
direction which is parallel to the sensitive axis of the sensor. This magnetic bias “pushes” the output to
a certain value, which is now a “psuedo zero” field point. The magnetic field from a current carrying
conductor is also directional. If a current flows in such a direction as to add to the biasing field, the
output from the sensor will increase. Likewise, if a current flows in the opposite direction, its resultant
field will subtract from the biasing field, and the output will decrease. This directionality can be seen
by looking at the output slopes of the previous two graphs. In the first graph, the output displayed
shows the current produced a field opposite to the biasing magnetic field. Thus showing as the current
increases, the output of the sensor decreases. In the same respect, the second graph shows that the field
from the current was in the same direction as the biasing field.
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AA003-02 over seven 0.010" wide
0.02
0.0023" thick traces
phone: [phone] fax: [phone]
0.04
Current (A)
mV Out = 177.74 ± 0.06(A)
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0.06
0.08
@8.06V
0.1
Application Notes
0.12