AA004-00

AA004-00E ETC2

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AA and AB-Series Analog Sensors - 12 - www.nve.com phone: 952-829-9217 fax: 952-829-9189 AA and AB-Series Analog Sensors NVE’s AA and AB-Series analog GMR sensors offer unique and unparalleled magnetic sensing capabilities. These sensors are characterized by high sensitivity to applied magnetic fields, excellent temperature stability, low power consumption, and small size. These characteristics make them suitable for use in a wide variety of applications from rugged industrial and automotive position, speed, and current sensors, to low-voltage, battery-powered sensors for use in hand-held instrumentation and implantable medical devices. The unmatched versatility of these basic magnetic sensors makes them an excellent choice for a wide range of analog sensing applications. The AA-Series sensors use NVE’s patented GMR materials and on-chip flux concentrators to provide a directionally sensitive output signal. These sensors are sensitive in one direction in the plane of the IC, with a cosine-scaled falloff in sensitivity as the sensor is rotated away from the sensitive direction. Also, these devices provide the same output for magnetic fields in the positive or negative direction along the axis of sensitivity (omnipolar output). All sensors are designed in a Wheatstone bridge configuration to provide temperature compensation. Two packages are offered, an SOIC8 and an MSOP8. These sensors are also available in die form on a special-order basis. There are three families of NVE’s basic AA-Series sensors: the standard AA-Series, the AAH-Series, and the AAL-Series. Each of these sensor families uses a different GMR material, with its own characteristics. The comparison table below summarizes the different characteristics of the GMR materials: Parameter AA Series AAH Series AAL Series Sensitivity to Applied Fields High Very High High Field Range of Operation High Low Medium Hysteresis Medium High Low Temperature Range High Very High Very High The AB-Series sensors are differential sensor devices, or gradiometers, which take advantage of the high output characteristics of NVE’s GMR materials. Two families of AB sensors are offered, the standard AB-Series and the ABH-Series. They have operational characteristics similar to the AA and AAH sensors described in the table above but with the bipolar linear output characteristics of a differential sensor. Within these different sensor families, customers can find an excellent match to their analog sensor requirements.

AA and AB-Series Analog Sensors - 13 - www.nve.com phone: 952-829-9217 fax: 952-829-9189 Quick Reference: AA and AB-Series For comparison and product selection purposes, the following table lists all available AA and AB- Series analog sensors, with some of their key characteristics: Magnetometers: Part Number Linear Range (|Oe Sensitivity (mV/V-Oe Maximum Non- linearity (% Uni. Maximum Hyster- esis (% Uni. Maximum Operating Temp (°C) Typical Resis- tance (Ohms) Package Min Max Min Max AA002-02 1.5 10.5 3.0 4.2 2 4 125 5K SOIC8 AA003-02 2.0 14 2 3.2 2 4 125 5K SOIC8 AA004-00 5.0 35 0.9 1.3 2 4 125 5K MSOP8 AA004-02 5.0 35 0.9 1.3 2 4 125 5K SOIC8 AA005-02 10.0 70 0.45 0.65 2 4 125 5K SOIC8 AA006-00 5.0 35 0.9 1.3 2 4 125 30K MSOP8 AA006-02 5.0 35 0.9 1.3 2 4 125 30K SOIC8 AAH002-02 0.6 3.0 11.0 18.0 6 15 150 2K SOIC8 AAH004-00 1.5 7.5 3.2 4.8 4 15 150 2K MSOP8 Gradiometers: Part Number Linear Range (|Oe Resistor Spacing (mm) Maximum Non- linearity (% Uni. Maximum Hyster- esis (% Uni. Maximum Operating Temp (°C) Typical Resis- tance (Ohms) Package Min Max AB001-02 20 200 0.5 2 4 125 2.5K SOIC8 AB001-00 20 200 0.5 2 4 125 2.5K MSOP8 ABH001-00 5 40 0.5 4 15 150 1.2K MSOP8 Notes: 1. Oersted (Oe) = 1 Gauss in air. 2. Unipolar operation means exposure to magnetic fields of one polarity, for example 0 to +30 Gauss, or -2 to -50 Gauss. Bipolar operation (for example, -5 to +10 Gauss) will increase nonlinearity and hysteresis

• 14 - www.nve.com phone: 952-829-9217 fax: 952-829-9189 AA Sensors Features:
• Excellent Sensitivity to Applied Magnetic Fields
• Wheatstone Bridge Analog Output
• Operating Temperature to 125°C Continuous
• Wide Linear Range of Operation
• Near-Zero Voltage Operation
• DC to >1MHz Frequency Response
• Small, Low-Profile Surface Mount Packages Applications:
• General Motion, Speed, and Position Sensing
• Low Power, Low Voltage Applications
• Low Field Sensing for Magnetic Media Detection
• Current Sensing Description: The basic AA-Series GMR sensors are general-purpose magnetometers for use in a wide variety of applications. They exhibit excellent linearity, a large output signal with applied magnetic fields, stable and linear temperature characteristics, and a purely ratiometric output. Magnetic Characteristics: Part Number Saturation Field (Oe Linear Range (|Oe Sensitivity (mV/V-Oe Resistance (Ohms) Package Die Size (µm) Min Max Min Max AA002-02 15 1.5 10.5 3.0 4.2 5K ±20% SOIC8 436x3370 AA003-02 20 2.0 14 2 3.2 5K ±20% SOIC8 436x3370 AA004-00 50 5 35 0.9 1.3 5K ±20% MSOP8 411x1458 AA004-02 50 5 35 0.9 1.3 5K ±20% SOIC8 411x1458 AA005-02 100 10 70 0.45 0.65 5K ±20% SOIC8 411x1458 AA006-00 50 5 35 0.9 1.3 30K ±20% MSOP8 836x1986 AA006-02 50 5 35 0.9 1.3 30K ±20% SOIC8 836x1986 GMR pin 5, OUT+ Functional Block Diagram shield shield pin 1, OUT- pin 4, V- (ground) pin 8, V+(supply) Orientation chamfer OUT - V- (ground) OUT+V+ (supply) Pin-out NVE AAxxx -02 Axis of Sensitivity NVE AAXXX-02 Pin 1

• 15 - www.nve.com phone: 952-829-9217 fax: 952-829-9189 General Characteristics: Parameter Min Typical Max Unit Input Voltage Range <1 Volts Operating Frequency DC >1 MHz Operating Temperature Range -50 125 °C Bridge Electrical Offset -4 +4 mV/V Signal Output at Max. Field 60 mV/V Nonlinearity 2 % (unipolar) Hysteresis 4 % (unipolar) TCR +0.14 % / °C TCOI +0.03 % / °C TCOV -0.1 % / °C Off Axis Characteristic Cos β ESD Tolerance 400 V pin-to-pin HBM Notes: 1. 1 Oersted (Oe) = 1 Gauss in air. 2. See the Appendix for package dimensions and tolerances. 3. Sensors can be provided in die form by special request. 4. GMR A A-Series sensors are pure ratiometric devices meaning that they will operate properly at extremely low supply voltages. The output signal will be proportional to the supply voltage. Maximum voltage range is limited by the power dissipation in the package and the maximum operating temperature of the sensor. 5. Unipolar operation means exposure to magnetic fields of one polarity, e.g., 0 to 30 Gauss, or 2 to -50 Gauss, but not -20 to +30 Gauss (bipolar operation). Bipolar operation will increase nonlinearity and hysteresis. 6. TCR is resistance change with temperature with no applied field. TCOI is the output change with temperature using a constant current source to power the sensor. TCOV is the output change with temperature using a constant voltage source to power the sensor. See the graphs below. 7. Beta ( β) is any angle deviation from the sensitive axis. AA002 Temperature Performance, 1m A Curre nt Supply -0.05 0.05 0.1 0.15 0.2 0.25 0.3 0.35 - 2 0 - 1 5 - 1 0- 5 0 5 1 01 52 0 Appli ed Ma gnetic Field (Oe) Output Voltage (V) -40C 25C 85C 125C A A002 Temp eratu re Perfo rmance, 5V Su pp ly -0.05 0.05 0.1 0. 1 5 0.2 0.25 0.3 0.35 -20 -1 5 -1 0 -5 0 5 1 0 1 5 20 Applied Magnetic Field (Oe) Output Voltage (V) -40C 25C 85C 125C

• 16 - www.nve.com phone: 952-829-9217 fax: 952-829-9189 AAH Sensors Features:
• Extremely High Sensitivity to Applied Magnetic Fields
• Wheatstone Bridge Analog Output
• Temperature Tolerance to 150°C Continuous
• Near-Zero Voltage Operation
• DC to >1MHz Frequency Response
• Small, Low-Profile Surface Mount Packages Applications:
• Low Voltage, High Temperature Applications
• Low Field Sensing for Magnetic Media Detection
• Earth’s Magnetic Field Detection
• Current Sensing Description: The AAH-Series GMR sensors are manufactured with a high sensitivity GMR material, making them ideally suited for any low magnetic field application. They are also extremely temperature tolerant, to +150°C operating temperatures. Magnetic Characteristics: Part Number Saturation Field (Oe Linear Range (|Oe Sensitivity (mV/V-Oe Resistance (Ohms) Package Die Size (µm) Min Max Min Max AAH002-02 6 0.6 3.0 11.0 18.0 2K ±20% SOIC8 436x3370 AAH004-00 15 1.5 7.5 3.2 4.8 2K ±20% MSOP 411x1458 GMR pin 5, OUT+ Functional Block Diagram shield shield pin 1, OUT- pin 4, V- (ground) pin 8, V+(supply) Orientation chamfer OUT - V- (ground) OUT+V+ (supply) Pin-out NVE AAxxx -02 Axis of Sensitivity NVE AAXXX-02 Pin 1

• 17 - www.nve.com phone: 952-829-9217 fax: 952-829-9189 General Characteristics: Parameter Min Typical Max Unit Input Voltage Range <1 ±12 Volts Operating Frequency DC >1 MHz Operating Temperature Range -50 150 °C Bridge Electrical Offset -5 +5 mV/V Signal Output at Max. Field 40 mV/V Nonlinearity 4 % (unipolar) Hysteresis 15 % (unipolar) TCR +0.11 % / °C TCOI +0.10 % / °C TCOV 0.0 % / °C Off Axis Characteristic Cos β ESD Tolerance 400 V pin-to-pin HBM Notes: 1. 1 Oersted (Oe) = 1 Gauss in air. 2. See the Appendix for package dimensions and tolerances. 3. Sensors can be provided in die form by special request. 4. GMR AAH-Series sensors are pure ratiometric devices meaning that they will operate properly at extremely low supply voltages . The output signal will be proportional to the supply voltage. Maximum voltage range is limited by the power dissipation in the package and the maximum operating temperature of the sensor. 5. Unipolar operation means exposure to magnetic fields of one polarity, e.g. 0 to 30 Gauss, or -2 to -50 Gauss, but not -20 to +30 Gauss (bipolar operation). Bipolar operation will increase nonlinearity and hysteresis. 6. TCR is resistance change with temperature with no applied field. TCOI is the output change with temperature using a constant current source to power the sensor. TCOV is the output change with temperature using a constant voltage source to power the sensor. 7. Beta ( β) is any angle deviation from the sensitive axis. AAH002 Temperature Performance, 2.28mA Current Source -0.05 0. 05 0.1 0. 15 0.2 0. 25 0.3 0. 35 0.4 - 2 0 - 1 5 - 1 0- 5 0 5 1 01 52 0 Applied Magnetic Field (Oe) Output Voltage (V) -40C 25C 85C 125C AAH002 Temperature Performance, 5V Supply -0.05 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 -20 -15 -10 -5 0 5 10 15 20 Appl ied Magnetic Field (Oe) Voltage Output (V) -40C 25C 85C 125C

• 18 - www.nve.com phone: 952-829-9217 fax: 952-829-9189 AAL Sensors Features:
• Excellent Sensitivity to Applied Magnetic Fields
• Wheatstone Bridge Analog Output
• Temperature Tolerance to 150°C Continuous
• Very Low Magnetic Hysteresis
• Near-Zero Voltage Operation
• DC to >1MHz Frequency Response
• Small, Low-Profile Surface Mount Packages Applications:
• General Motion, Speed, and Position Sensing
• Low Voltage, High Temperature Applications
• Low Field Sensing for Magnetic Media Detection
• Current Sensing Description: The AAL-Series GMR sensors are manufactured with a low hysteresis GMR material, for use in magnetometer applications where minimum hysteresis is important. They are also extremely temperature tolerant, to +150°C operating temperatures. Magnetic Characteristics: Part Number Saturation Field (Oe Linear Range (|Oe Sensitivity (mV/V-Oe Resistance (Ohms) Package Die Size (µm) Min Max Min Max GMR pin 5, OUT+ Functional Block Diagram shield shield pin 1, OUT- pin 4, V- (ground) pin 8, V+(supply) Orientation chamfer OUT - V- (ground) OUT+V+ (supply) Pin-out NVE AAxxx -02 Axis of Sensitivity NVE AAXXX-02 Pin 1

• 19 - www.nve.com phone: 952-829-9217 fax: 952-829-9189 General Characteristics: Parameter Min Typical Max Unit Input Voltage Range <1 ±25 Volts Operating Frequency DC >1 MHz Operating Temperature Range -50 150 °C Bridge Electrical Offset -4 +4 mV/V Signal Output at Max. Field 45 mV/V Nonlinearity 2 % (unipolar) Hysteresis 4 % (unipolar) TCR +0.11 % / °C TCOI -0.28 % / °C TCOV -0.40 % / °C Off Axis Characteristic Cos β ESD Tolerance 400 V pin-to-pin HBM Notes: 1. 1 Oersted (Oe) = 1 Gauss in air. 2. See the Appendix for package dimensions and tolerances. 3. Sensors can be provided in die form by special request. 4. GMR AAL-Series sensors are pure ratiometric devices meaning that they will operate properly at extremely low supply voltages . The output signal will be proportional to the supply voltage. Maximum voltage range is limited by the power dissipation in the package and the maximum operating temperature of the sensor. 5. Unipolar operation means exposure to magnetic fields of one polarity, e.g. 0 to 30 Gauss, or -2 to -50 Gauss, but not -20 to +30 Gauss (bipolar operation). Bipolar operation will increase nonlinearity and hysteresis. 6. TCR is resistance change with temperature with no applied field. TCOI is the output change with temperature using a constant current source to power the sensor. TCOV is the output change with temperature using a constant voltage source to power the sensor. 7. Beta ( β) is any deviation angle from the sensitive axis. AAL002 Temperature Performance, 1mA Current Supply -0.05 0.05 0.1 0.15 0.2 0.25 0.3 0.35 -30 -20 -10 0 10 20 30 Appl ied Magnetic Fi eld (Oe) Output Voltage (V) -40C 25C 85C 125C AAL002 Temperature Performance, 5V Supply -0.05 0.05 0.1 0.15 0. 2 0.25 0. 3 0.35 -30 -20 -1 001 0 2 0 3 0 Applied Magne tic Fie ld (Oe) Output Voltage (V) -40C 25C 85C 125C

• 20 - www.nve.com phone: 952-829-9217 fax: 952-829-9189 AAV Sensors Features:
• Operates in Magnetic Saturation, 30 to 200 Gauss
• Half-Bridge or Individual Resistor Configurations
• Sine and Cosine Outputs Available
• Utilizes Spin Valve GMR Material
• Precise Detection of Magnetic Field
• Ultra-Small PLLP Package
• Cannot Be Damaged by Large External Magnetic Fields Description: The AAV001-11 and AAV002-11 are arrays of four GMR resistors rotated at 90-degree intervals in the package. The AAV001-11 features independent resistors that can be wired together to form two half-bridges, or used as independent resistors. The AAV002-11 has the bridge connections made internally to the package. For either part, the output can be configured to represent the sine and cosine function of the magnetic field being applied to the sensor. Each resistor is 1.5 kΩ nominal resistance and output of each half-bridge is ratiometric with the power supply voltage. The part features NVE’s PLLP6 housing, which is a 3.0 mm x 3.0 mm x 0.9 mm thick surface mount package. Operation: The sensor elements contain two magnetic layers: a pinned, or fixed-direction layer, and a movable or free layer. The diagram below illustrates the configuration with arrows representing the two layers: Pinned LayerFree Layer Angle Between Pinned and Free Layers Determines Electrical Resistance of Sensor Applied Magnetic Field(30 to 200 Gauss) Free Layer Aligns with the Applied Magnetic Field

• 21 - www.nve.com phone: 952-829-9217 fax: 952-829-9189 The end user must apply a saturating magnetic field (30 to 200 Oersteds) in the plane of the sensor in order for the sensor to operate. The movable layer will align with the applied magnetic field. As the applied field changes direction the angle between the movable layer and the pinned layer changes, resulting in a change of resistance in the device. A graph of the device resistance vs. the angle between the pinned layer and the movable layer is shown below: Four individual sensor resistors are supplied in the package, each with the pinned layer rotated 90º with respect to that of the previous sensor. These resistors can be connected in two half-bridge configurations to provide a sine and cosine output or monitored individually to provide an absolute indication of the angle between the pinned layer and the movable layer. Resistance Change of Spin Valve Sensor Element 1420 1430 1440 1450 1460 1470 1480 1490 1500 1510 1520 09 0 1 8 0 2 7 0 3 6 0 Angle Between Pinned and Movable Layers Resistance (Ohms)

• 22 - www.nve.com phone: 952-829-9217 fax: 952-829-9189 A drawing showing the ICs position in the package is given below. On each IC there is an arrow indicating the direction of the pinned layer. Functional Block Diagram, Marking, and Pinout, AAV001-11: BBP R3 (Cosine) R1 (Sine) R2 (Sine) R4 (Cosine) VCC GND Sine Output Cosine Output

• 23 - www.nve.com phone: 952-829-9217 fax: 952-829-9189 Functional Block Diagram, Marking, and Pinout, AAV002-11: Specifications: Parameter Test Condition Min Typ Max Units Nominal Resistance of Each Resistor 25°C 1200 1500 1800 Ohms Maximum Resistance Decrease with Field Change Operating at 25°C 4.5% 5.2% 7% Required Strength of Applied Magnetic Field Operating 30 200 Oersted Measurement Error Operating 2 Degrees Supply Voltage Operating 12 Volts Offset Voltage Operating at 25°C -10 10 mV/V Temperature Range of Operation Operating -40 150 °C Storage Temperature -40 170 °C Temperature Coefficient of Resistance Operating +0.3 %/°C TCOV Operating -0.24 %/°C TCOI Operating -0.16 %/°C Notes: 1. Large Magnetic Fields WILL NOT cause damage to NVE GMR Sensors. 2. 1 Oe (Oersted) = 1 Gauss in air = 0.1 mTesla = 79.8 Amps/meter. 3. TCOV is the percent change in output signal over temperature with a constant voltage source powering the part and TCOI is the percent change in output over temperature with a constant current source. BBQ R3 (Cosine) R4 (Cosine) R2 (Sine) R1 (Sine) VCC Cos GND SinCosine Output Sine Output

• 24 - www.nve.com phone: 952-829-9217 fax: 952-829-9189 AB Sensors Features:
• Excellent Sensitivity to Applied Magnetic Fields
• Wheatstone Bridge Analog Output
• Temperature Tolerance to 125°C Continuous
• Wide Linear Range of Operation
• Near-Zero Voltage Operation
• DC to >1MHz Frequency Response
• Small, Low-Profile Surface Mount Packages Applications:
• General Differential Field Sensing
• Gear Tooth and Encoder Speed and Position Sensing
• Low Power, Low Voltage Applications Description: The AB-Series GMR sensors are general-purpose gradiometers for use in a wide variety of applications. Two pairs of unshielded GMR sensor elements provide for directional sensing of small gradients in large and small magnetic fields. The ability to detect only magnetic gradients allows low sensitivity to external sources of uniform magnetic field allowing these sensors to work successfully in high magnetic noise environments such as near electric motors or current carrying wires V- (ground) OUT B Pin 1 OUT A V+ (supply) Pinout NVE ABxxx-02 Axis of Sensitivity X Y GMR pin 5, OUT B Functional Block diagram pin 1, OUT A pin 4, V- (ground) pin 8, V+(supply) Y YX X Magnetic Characteristics: Part Number Saturation Field (Oe Linear Range (|Oe Resistor Sensitivity (%R / Oe Resistance (Ohms) Package Die Size (µm) Min Max Min Max AB001-02 250 10 175 0.02 0.03 2.5K ±20% SOIC8 651x1231 AB001-00 250 10 175 0.02 0.03 2.5K ±20% MSOP8 651x1231

• 25 - www.nve.com phone: 952-829-9217 fax: 952-829-9189 General Characteristics: Parameter Min Typical Max Unit Input Voltage Range <1 ±12.5 Volts Operating Frequency DC >1 MHz Operating Temperature Range -50 125 °C Bridge Electrical Offset -4 +4 mV/V Signal Output at Max. Field 120 mV/V Nonlinearity 2 % (unipolar) Hysteresis 4 % (unipolar) TCR +0.14 % / °C TCOI +0.03 % / °C TCOV -0.1 % / °C Off Axis Characteristic Cos β ESD Tolerance 400 V pin-to-pin HBM Notes: 1. 1 Oersted (Oe) = 1 Gauss in air. 2. See the Appendix for package dimensions and tolerances. 3. Sensors can be provided in die form by special request. 4. GMR A B-Series sensors are pure ratiometric devices, meaning that they will operate properly at extremely low supply voltages. The output signal will be proportional to the supply voltage. Maximum voltage range is limited by the power dissipation in the package and the maximum operating temperature of the sensor. 5. Unipolar operation means exposure to magnetic fields of one polarity, e.g., 0 to 30 Gauss, or -2 to -50 Gauss, but not -20 to +30 Gauss (bipolar operation). Bipolar operation will increase nonlinearity and hysteresis. 6. TCR is resistance change with temperature with no applied field. TCOI is the output change with temperature using a constant current source to power the sensor. TCOV is the output change with temperature using a constant voltage source to power the sensor. 7. Beta ( β) is any angle deviation from the sensitive axis. The Figure at left is a simulated output from an NVE Gradiometer. The output / gradient correlation shown assumes one pair of resistors is held at zero field. Note the bipolar output. Typical Gradiometer Transfer Function -50 -40 -30 -20 -10 -400 -200 0 200 400 Magnetic Field Applied to Resistors Differential Voltage Out of Sensor (mV) Increasing field on X resistors Increasing field on Y resistors

• 26 - www.nve.com phone: 952-829-9217 fax: 952-829-9189 ABH Sensors Features:
• Extremely High Sensitivity to Applied Magnetic Fields
• Wheatstone Bridge Analog Output
• Temperature Tolerance to 150°C Continuous
• Wide Linear Range of Operation
• Near-Zero Voltage Operation
• DC to >1MHz Frequency Response
• Small, Low-Profile Surface Mount Packages Applications:
• General Differential Field Sensing
• Gear Tooth and Encoder Speed and Position Sensing
• Low Voltage, High Temperature Applications Description: The ABH-Series GMR sensors are low field, high temperature gradiometers for use in a wide variety of applications. Two pairs of unshielded GMR sensor elements provide for directional sensing of small gradients in large and small magnetic fields. The ability to detect only magnetic gradients allows low sensitivity to external sources of uniform magnetic field allowing these sensors to work successfully in high magnetic noise environments such as near electric motors or current carrying wires. V- (ground) OUT B Pin 1 OUT A V+ (supply) Pinout NVE ABxxx-02 Axis of Sensitivity X Y GMR pin 5, OUT B Functional Block diagram pin 1, OUT A pin 4, V- (ground) pin 8, V+(supply) Y YX X Magnetic Characteristics: Part Number Saturation Field (Oe Linear Range (|Oe Resistor Sensitivity (%R / Oe Resistance (Ohms) Package Die Size (µm) Min Max Min Max ABH001-00 70 5 40 0.06 0.12 1.2K ±20% MSOP8 651x1231

• 27 - www.nve.com phone: 952-829-9217 fax: 952-829-9189 General Characteristics: Parameter Min Typical Max Unit Input Voltage Range <1 Volts Operating Frequency DC >1 MHz Operating Temperature Range -50 150 °C Bridge Electrical Offset -4 +4 mV/V Signal Output at Max. Field 80 mV/V Nonlinearity 4 % (unipolar) Hysteresis 15 % (unipolar) TCR +0.11 % / °C TCOI +0.10 % / °C TCOV 0.0 % / °C Off Axis Characteristic Cos β ESD Tolerance 400 V pin-to-pin HBM Notes: 1. 1 Oersted (Oe) = 1 Gauss in air. 2. See the Appendix for package dimensions and tolerances. 3. Sensors can be provided in die form by special request. 4. GMR A B-Series sensors are pure ratiometric devices meaning that they will operate properly at extremely low supply voltages. The output signal will be proportional to the supply voltage. Maximum voltage range is limited by the power dissipation in the package and the maximum operating temperature of the sensor. 5. Unipolar operation means exposure to magnetic fields of one polarity, e.g., 0 to 30 Gauss, or -2 to -50 Gauss, but not -20 to +30 Gauss (bipolar operation). Bipolar operation will increase nonlinearity and hysteresis. 6. TCR is resistance change with temperature with no applied field. TCOI is the output change with temperature, using a constant current source to run the sensor. TCOV is the output change with temperature, using a constant voltage source to run the sensor. 7. Beta ( β) is any angle deviation from the sensitive axis. The Figure at left is a simulated output from an NVE Gradiometer. The output / gradient correlation shown assumes one pair of resistors is held at zero field. Note the bipolar output. Typical Gradiometer Transfer Function -50 -40 -30 -20 -10 -400 -200 0 200 400 Magnetic Field Applied to Resistors Differential Voltage Out of Sensor (mV) Increasing field on X resistors Increasing field on Y resistors