AG003-01E NVE, AG003-01E Datasheet - Page 85

• Manufacturer Part Number: AG003-01E
• Description: ASSEMBLY CURRENT SENSOR EVAL
• Manufacturer: NVE

Specifications of AG003-01E

• Sensor Type: Magnetic. GMR (Giant Magnetoresistive)
• Interface: Analog
• Embedded: No
• Utilized Ic / Part: AA Series Current Sensors
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Supply: -
• Sensitivity: -
• Sensing Range: -
• Other names: 391-1060

Temperature Characteristics of GMR Sensors
Temperature excursions cause several changes to the characteristics of GMR sensors. The changes are
described below:
For purposes of temperature compensation, a single resistor sensor element made from GMR material
can be modeled as two resistors in series. The first resistor is the base resistive element, and is a
constant resistance at a given temperature, regardless of the applied magnetic field. The second resistor
represents the changing resistance of the single resistor sensor element made from GMR material, as
magnetic field is applied. This model is shown in the following diagram:
The base resistance of R1 is the resistance of the sensor element at 25°C when the saturating magnetic
field is applied and R2 has dropped to 0 resistance; in other words, the minimum resistance of the
sensor element as described in the GMR Material Physics section. The following formula can be used
to compute R1 at various temperatures:
R1 = R1 Base Resistance * [ 1 + (TCR * (Temperature - 25°C))]
The resistance of R2 in the diagram varies both with the temperature and the applied magnetic field.
The base resistance of R2 is defined as its maximum resistance at 25°C. This is the resistance with zero
applied magnetic field. The base resistance of R2 will vary with temperature (at zero applied field) as
described by the following formula:
R2
Zero Field
1. Changes to base resistance of the sensor element [TCR] – This is a temperature coefficient of
2. Changes to the % GMR of the sensor element [TCGMR] – When a magnetic field is applied,
3. Changes to the saturation field of the sensor element [TCHsat] – The magnetic field at which
= R2 Base Resistance * [ 1 + (TCGMR * (Temperature - 25°C))]
resistance of the sensor element with no applied magnetic field to the sensor. The TCR is
normally given in %/ºC.
the % GMR exhibited by the sensor element will change. Generally as temperature increases,
% GMR decreases. TCGMR is normally given in %/ºC.
the sensor will provide its maximum output will also change with temperature. The saturation
field (Hsat) will decrease as temperature increases. TCHsat is normally given in %/ºC.
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Resistance
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Base
R1
- 85 -
Resistance
GMR
R2
Application Notes