Two sensors in each electric power steering system will have to accurately and constantly gauge the active level of steering torque. To achieve this they must measure the steering force exerted and the steering angle and then feed this data to the control unit of the electric power steering system. This unit then ensures that the control of the motor responsible for the electric power steering is optimized relative to the steering force and energy required.
Fundamentally, the TLE4998 Hall sensors are well suited for applications requiring accurate rotation and position detection. Automotive applications can include pedal, throttle, or gear stick position detection, suspension control, and direct torque sensing for electric power steering systems.
These Hall sensors have operational characteristics that fit well with this particular design-in. Automotive applications always provide design challenges when it comes to electronic components and systems. These challenges manifest themselves in a variety of ways that include extreme temperature variations, vibration, interfering electrical noise, harsh geographic conditions, and on some occasions, poor maintenance procedures.
Although poor maintenance is impossible to design-out of any system, these particular sensors cope well with difficult temperatures. And because they’re inherently stable in design, they can cope with automotive operating stresses.
Three Interfaces
The TLE4998 Hall sensors support system reliability via a protected digital interface. Infineon Hall sensors provide three interfaces: short PWM codes (SPC), pulse width modulation (PWM), and single edge nibble transmission (SENT). In this way, Infineon supports the conversion from analog to digital communication between the sensor and control unit of the vehicle steering system.
The SPC interface enhances the accuracy and reliability in safety-critical automotive applications as it allows synchronized data transmission with the control unit. This functionality means the microcontroller in the control unit can selectively collect sensor measurement data for processing and always has current measurement data available.
The TLE4998 family includes three interface versions: the TLE4998C (SPC), TLE4998P (PWM), and TLE4998S (SENT).