AAT001-10E

Data Sheet AAT001-10E TMR Angle Sensor Key Features • Tunneling Magnetoresistance (TMR) Technology • Very High Output Signal Without Amplification • Wide Airgap Tolerance • Very High Resistance for Extremely Low Power • Sine and Cosine Outputs Available • Ultraminiature TDFN6 Package Typical Applications • Rotary Encoders • Automotive Rotary Position Sensors • Motor Shaft Position Sensors • Knob Position Sensors Description The AAT001-10E angle sensor is a unique array of four Tunneling Magnetoresistance (TMR) elements rotated at 90 degree intervals in the package and connected in a bridge configuration. The output can be configured to represent the sine and cosine functions of the magnetic field applied to the sensor. Each TMR sensor element has a resistance of approximately 1.25 megaohms. Outputs are proportional to the supply voltage and peak-to-peak output voltages are much larger than other sensor technologies. The part is packaged in NVE’s 2.5 mm x 2.5 mm x 0.8 mm TDFN6 surface mount package. Operation Each sensor elements contain two magnetic layers: a “pinned,” or fixed direction layer; and a movabledirection, or “free” layer. The diagram below illustrates the configuration, using arrows to represent the two layers: Angle between Pinned and Free layers determines sensor resistance pli ed (30 Ma to gne 20 tic 0 O Fi e) eld Pinned Layer Fr e eL Free layer aligns with Applied Magnetic Field Ap Rhopoint Components www.rhopointcomponents.com ay er AAT001-10E TMR Sensor An external magnet provides a saturating magnetic field (30 to 200 Oe) in the plane of the sensor, as illustrated below for a bar magnet and a split-pole magnet: The sensor element free layers will align with the external field. As the applied field changes direction, the angle between the free layer and the pinned layer changes, changing the resistance of TMR elements, which changes the device output voltages. Variations in the air gap between the magnet and the sensor element will cause slight changes in the output depending on the size and strength of the external magnet. The following chart shows a typical sensor output versus the angle of applied field using a 12 mm diameter, 4 mm thick split-pole ferrite magnet and a 5 V supply with three different air gaps: Angle Sensor Output with Variations in Airgap, 5V Supply 2.9 Cosine, 3mm 2.8 2.7 2.6 Voltage Sine, 3mm Cosine, 4mm Sine, 4mm Cosine, 5mm Sine, 5mm 2.5 2.4 2.3 2.2 2.1 2 0 24 48 72 96 120 144 168 192 216 240 264 288 312 336 360 Degrees of Rotation Rhopoint Components www.rhopointcomponents.com AAT001-10E TMR Sensor Functional Block Diagram, Marking, and Pinout The AAT001-10E package is marked “FCVe.” The device contains four sensing resistors with the pinned layer 90 degrees apart. The resistors are connected as two half-bridges, providing sine and cosine outputs: FCVe Vcc Vcc R3 (Cosine) R2 (Sine) Cosine Output Cos Sin Sine Output R4 (Cosine) GND R1 (Sine) GND Operating Specifications Parameter Resistance (Each Resistor) Peak-to-Peak Signal Level Required Applied Magnetic Field Strength Angular Measurement Error Supply Voltage Offset Voltage Temperature Range of Operation Temperature Coefficient of Resistance TCOV3 Test Condition 25°C Operating at 25°C Operating Operating Operating Operating at 25°C Operating Operating Operating Min. 0.6 130 30 −10 −40 +0.09 −0.13 Typ. 1.25 160 Max. 2.5 180 200 3 5.5 10 125 Units MΩ mV/V Oe2 Angular Degrees V mV/V °C %/°C %/°C Absolute Maximum Ratings Parameter Supply Voltage Storage Temperature ESD (Human Body Model) Applied Magnetic Field1 Min. −40 Typ. Max. 7 170 2,000 Unlimited Units Volts °C Volts Oe Notes: 1. 2. 3. 4. Large magnetic fields CANNOT damage NVE sensors. 1 Oe (Oersted) = 1 Gauss in air = 0.1 millitesla = 79.8 A/m. TCOV is the percent change in voltage signal over temperature with a constant supply voltage. Resistance is specified with the saturating magnetic field applied. Rhopoint Components www.rhopointcomponents.com AAT001-10E TMR Sensor Package Drawing – TDFN6 2.5 mm x 2.5 mm RoHS COMPLIANT Notes: • Dimensions in mm. • The center pad may be left floating or connected to ground. The information provided by NVE Corporation is believed to be accurate. However, no responsibility is assumed by NVE Corporation for its use, nor for any infringement of patents, nor rights or licenses granted to third parties, which may result from its use. No license is granted by implication, or otherwise, under any patent or patent rights of NVE Corporation. NVE Corporation does not authorize, nor warrant, this product for use in life support devices or systems or other critical applications. Specifications are subject to change without notice. SB-00-024; March 11, 2009 Rhopoint Components www.rhopointcomponents.com