TAS Series TMR Angle Sensors
TDK’s TAS series TMR angle sensors for automotive applications
TDK's TAS series angle sensors provide high output, high accuracy, and high stability by utilizing a tunnel magnetoresistance (TMR) element. This TMR element was developed using TDK’s thin-film technology that has been accumulated through the production of HDD heads. A TMR element consists of three layers: a pin layer, a barrier layer, and a free layer. The barrier layer is made of a thin insulator and is sandwiched between the pin and free layer, which are both made of ferromagnetic material. The magnetization direction of the pin layer is fixed and the magnetization direction of the free layer changes according to the external magnetic field direction. When the magnetization directions of the free layer and the pin layer are parallel, the electrical resistance of the element becomes small and causes a large current to flow into the barrier layer. When the free layer and pin layer are antiparallel, the electrical resistance becomes large and virtually no current flows into the barrier layer.
When a magnet is rotated on a TMR sensor, the magnetization direction of the free layer follows the magnetic field direction of that magnet and the resistance of the element changes continuously. This resistance value is proportional to the relative angle between the magnetization directions of the pin layer and the free layer meaning the element can be used as an angle sensor for 360° angle detection.
TDK’s TAS series TMR angle sensors have an output that is 20 times higher than that of an AMR sensor, and 6 times higher than that of a GMR sensor. The TAS series also features low power consumption, low aging deterioration, and maintains stable angle accuracy in a broad temperature range (angle error of ±0.6° or less in the magnetic field range of 20 mT to 80 mT at temperatures ranging from -40°C to +150°C), making them ideal for use in automotive and industrial applications.
Additional Information: TAS Tech Notes
- High output at 1.5 VPP/3.0 VPP @ 5 V
- Good angular accuracy of ±0.6° (1.5 VPP differential output @ 5 V) and ±0.8° (3.0 VPP differential output @ 5 V)
- Low temperature drifts
- Low power consumption
- Detections can be made from 0° to 360°
- Operating temperature: -40°C to +150°C
- Steering angles
- Pedal opening, throttle valve opening
- Brushless motors
- Motors for wipers