AG920-07E NVE, AG920-07E Datasheet - Page 105

• 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

Noise In NVE Giant Magnetoresistive Sensors
The 1/f noise characteristic of NVE GMR sensors is approximately an order of magnitude higher than
noise for thin film resistors. The noise has been shown to follow the usual characteristics of being
proportional to the square of the current density. The figure below shows a noise plot of an AA002-02
sensor using various methods for powering the sensor:
For use in low-field applications, the noise of the NVE GMR sensors limits the minimum signal
detected. For measuring low fields it is recommended that an AC modulation/demodulation scheme be
implemented. The figure below shows a block diagram of an AC modulation/demodulation circuit.
The phase shifter block is required to account for parasitic phase shift around the loop.
100000
10000
1000
100
10
0.01
8 Vin+
4 Vin-
0.1
www.nve.com
1 Vout-
5 Vout+
1
AA002-02 Spectrum Analysis 6/10/98
RG
phone: [phone] fax: [phone]
GENERATOR
SINE WAVE
+
RG1
RG2
-
Log Frequency (Hz)
10
- 105 -
INST AMP
100
PHASE SHIFTER
IN1
IN2
1000
OUT
Application Notes
Rf
10000
9V Battery
1.616 mA
18V Battery
3.233 mA
479 nA Blue
Box
498 uA Blue
Box
2.003 mA
Blue Box
Cf
Vout
100000