Magnetic speed sensors

Magnetic speed sensors with GMR-based and Hall effect technology

Infineon’s magnetic speed sensors use GMR-based and Hall effect technology to determine linear and rotational speed. A magnetoresistive GMR speed sensor determines its measurement from the change of resistance of its sensing element caused by the change in the applied magnetic field. A Hall effect speed sensor makes use of the Hall effect, which refers to the creation of a voltage when a magnetic field is placed perpendicularly to a semiconductor with a current running through it. 

High electromagnetic robustness and electrostatic discharge protection

Our magnetic speed sensor ICs also feature benefits like integrated capacitors for high electromagnetic (EMC) robustness and the highest levels of electrostatic discharge (ESD) protection. In addition to a wide range of automotive uses, Infineon speed sensors serve as valuable technologies in industrial settings, measuring speed, achieving CO2 targets, and bringing about smart, secure powertrain solutions.  

Ideal all-purpose magnetic speed sensors for wheel speed sensing

As car technologies have advanced, wheel speed has become an essential measurement for a wide range of modules, necessitating cutting-edge magnetic speed sensors that accurately measure and report wheel speed. Tire Pressure Monitoring Systems (TPMS) use complex algorithms to determine if a wheel lacks air pressure. Central locking locks the doors after a couple of meters of movement. These are all examples of where magnetic wheel speed sensors are now required to relay accurate data so that various other modules can operate. 

Our best-selling TLE4941plusC magnetic speed sensor is an industry-standard for wheel speed sensing. The similar TLE4942-1C and TLE4943C complement this sensor by reporting additional direction information via pulse-width modulation (PWM) or AK protocols respectively. As a single-chip magnetic wheel speed sensor, it measures the car’s wheel speed magnetically using Hall effect technology. It’s the ideal all-purpose magnetic speed sensor, equally effective for pole wheel and steel wheel applications. Their differential principles immunize these sensors from undesired magnetic stray fields, ferromagnetic particles, or other disturbances.

TLE4941plusC

Hall effect speed sensors for high-end transmission applications

Infineon’s TLE4953C differential Hall effect automatic transmission speed sensor was developed specifically to detect direction and meet the needs of high-end transmission applications. Its jitter performance and high sensitivity let designers create high-accuracy systems with excellent vibration suppression. Adaptive hysteresis and dynamic self-calibration algorithms ensure outstanding measurement results with fine as well as coarse target wheels. As with other Infineon magnetic speed sensors, the south and north poles can be pre-inducted.

TLE4955 is the most recent family of differential Hall effect sensors specifically designed to meet the latest transmission vibration suppression requirements. It provides best-in-class vibration suppression for applications that require a two-wire current interface. Our TLE4955 family provides a similar algorithm as well as dynamic self-calibration, jitter, and sensitivity levels. Their main features include the detection of rotation direction, highly accurate speed measurements from zero to 12 kHz, excellent vibration suppression, and a broad operating temperature range. Designers can choose between different interface protocol versions.

TLE4953C

TLE4953

Highest accuracy speed measurement in safety & powertrain applications

Technological advancements in automobiles have led to magnetic speed sensors being widely used across automotive applications. In addition to Hall effect wheel speed sensors, automatic transmission speed sensors and magnetic crankshaft speed sensors monitor the rotational speed of an engine’s crankshaft. Engine management systems use this data to control essential engine components, such as ignition and flow of fuel. Similarly, camshaft speed sensors regulate the relationship between an engine’s pistons and valves, essential for both the injection of fuel into the engine and the release of exhaust. 

Relatedly, magnetic speed sensors have seen increased usage in industrial settings, providing rotational speed measurements for a range of applications. Prominent examples include speed sensors that can be used to report back on web processes and robotic arm movements or measure the gear and belt speed and positioning.