AG933-07E

AG933-07E AAT009 6MΩ Angle Sensor Evaluation Kit SB-00-050 NVE Corporation (800) 467-7141 sensor-apps@nve.com www.nve.com Kit Overview Evaluation Kit Features • AAT009-10E ultralow-power angle sensor • Part # 12426 split-pole Alnico 5 round horseshoe magnet • Unity-gain op amp buffer • 1.5 V to 5.5 V supply range • Magnet locating fixture AAT009-10E Features • Tunneling Magnetoresistance (TMR) technology • 6 MΩ typical bridge resistance for ultralow power • 200 mV/V typical output signal • 0.5 degree max. error (constant field) • Wide magnet airgap tolerance • Sine and cosine outputs for direction detection • Ultraminiature 2.5 mm x 2.5 mm x 0.8 mm TDFN6 package AAT-Series Sensor Applications • Rotary encoders • Motor shaft position sensors • Internet-of-Things sensor nodes • Battery or harvested power Part Number AAT001-10E AAT003-10E AAT009-10E Typ. Device Resistance 1.25 M 40 k 6M Features Ultra-low power Ideal for interface to microcontrollers Ultra-ultra-low power AAT009-10E Angle Sensor Description The AAT009-10E angle sensor is a ultralow power, high output magnetic sensor element for position measurements based on a rotating magnetic field. Typical device resistance is 6 MΩ, minimizing power consumption and allowing years of operation from button cells or harvested power. Visit www.nve.com for complete product specifications. Quick Start ⇒ Connect VCC1 and VCC2 to a 3.3 or 5 V supply. ⇒ Connect the “SIN” and “COS” screw terminals to an oscilloscope or to meters. ⇒ Place the split-pole magnet in the Plexiglas pocket. ⇒ Rotate the magnet. VOLTAGE ⇒ The outputs should be similar to the following graph: 3 Sin 2.75 2.5 Cos 2.25 2 0 90 180 270 ROTATION 360 The output is insensitive to magnet spacing over a wide range. Signal is lost if the magnet is too far away; if the magnet is too close the outputs will be nonsinusoidal. A relatively large magnet-sensor airgap is possible with the magnet provided with the kit, although smaller magnets will require a smaller gap. Evaluation Board Layout AAT009-10E Angle Sensor 100 nF decoupling capacitor Dual unity-gain op amp buffer Large output signal Wide airgap tolerance Low power 5.5V max. sensor supply input VCC1 = 5.5V Max VCC2 = 1.5V to 5.5V Angular reticle (10° per division) 1.5V to 5.5V buffer power supply input GND RAW SIN 10° per division FDZe Pocket for split-pole magnet RAW COS VCC1 VCC2 SIN COS GND GND www.nve.com (800) GMR-7141 Raw sensor outputs (unbuffered) AG933-06 ©NVE Corporation © Buffered Sin and Cos outputs Principles of Operation Each of the four sensor elements contains two magnetic layers: a “pinned,” or fixed direction layer; and a movable-direction, or “free” layer. Internal sensor pairs are 90° out of phase to provide quadrature outputs. The diagram below illustrates the configuration, using arrows to represent the magnetic orientation of the layers: Pinned Layer Fr ee La ye r Free layer aligns with applied magnetic field Ap pli ed (30 Ma to gne 20 tic 0 O Fi e) eld Angle between pinned and free layers determines sensor resistance 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 spintronic Tunneling Magnetoresistance (TMR) elements, which changes the device output voltages. In the typical configuration, an external magnet provides a saturating magnetic field (30 to 200 Oe) in the plane of the sensor, as demonstrated in this kit. Depending on the application, a bar magnet can also be used instead of a splitpole magnet. PCB Assembly AAT009-10E AAT003-10E 1 Vcc 100 nF R3 (Cosine) 6 Vcc - R2 (Sine) 5 Sin 2 Cos 1.5 V to 5.5 V R1 (Sine) 0V to 5.5 V + VCC1 VCC2 SIN COS GND Raw Sin Raw Cos GND 3 R4 (Cosine) GND 4 + TSV622 100 nF AG933-07E Evaluation Kit schematic. The PCB assembly includes a unity-gain buffer for low-impedance outputs that prevent downstream electronics from loading the sensor bridge. Buffering may not be necessary in the end application depending on the impedance of downstream electronics. Raw output signals from the AAT009 are also available as test points, however an unpowered buffer will load the sensor, so the buffer should be either powered or removed to use the raw outputs. Separate supply connections for the sensor and op amp (VCC1 and VCC2) allow monitoring the sensor supply current only, or VCC1 and VCC2 can be connected together. The op amp has a 1.5 V minimum supply voltage, while the sensor has no minimum. Sensitivity increases proportionately to the sensor supply voltage, as does current consumption. Limited Warranty and Liability Information in this document is believed to be accurate and reliable. However, NVE does not give any representations or warranties, expressed or implied, as to the accuracy or completeness of such information and shall have no liability for the consequences of use of such information. In no event shall NVE be liable for any indirect, incidental, punitive, special or consequential damages (including, without limitation, lost profits, lost savings, business interruption, costs related to the removal or replacement of any products or rework charges) whether or not such damages are based on tort (including negligence), warranty, breach of contract or any other legal theory. Right to Make Changes NVE reserves the right to make changes to information published in this document including, without limitation, specifications and product descriptions at any time and without notice. Use in Life-Critical or Safety-Critical Applications Unless NVE and a customer explicitly agree otherwise in writing, NVE products are not designed, authorized or warranted to be suitable for use in life support, life-critical or safety-critical devices or equipment. NVE accepts no liability for inclusion or use of NVE products in such applications and such inclusion or use is at the customer’s own risk. Should the customer use NVE products for such application whether authorized by NVE or not, the customer shall indemnify and hold NVE harmless against all claims and damages. Applications Applications described in this document are illustrative only. NVE makes no representation or warranty that such applications will be suitable for the specified use without further testing or modification. Customers are responsible for the design and operation of their applications and products using NVE products, and NVE accepts no liability for any assistance with applications or customer product design. It is customer’s sole responsibility to determine whether the NVE product is suitable and fit for the customer’s applications and products planned, as well as for the planned application and use of customer’s third party customers. Customers should provide appropriate design and operating safeguards to minimize the risks associated with their applications and products. NVE does not accept any liability related to any default, damage, costs or problem which is based on any weakness or default in the customer’s applications or products, or the application or use by customer’s third party customers. The customer is responsible for all necessary testing for the customer’s applications and products using NVE products in order to avoid a default of the applications and the products or of the application or use by customer’s third party customers. NVE accepts no liability in this respect. An ISO 9001 Certified Company NVE Corporation 11409 Valley View Road Eden Prairie, MN 55344-3617 ©NVE Corporation All rights are reserved. Reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. Manual No.: SB-00-050