Infineon Angle Sensors Double Down on Accuracy and Stray Field Immunity

Infineon recently introduced the XENSIV TLE49SR, a cutting-edge angle sensor falling under the category of "Magnetic Sensors - Compass, Magnetic Field (Modules)." This innovative sensor is designed to provide precise automotive angular measurements for applications such as chassis height, pedal position, throttle position, and steering angle sensors. Infineon praises the TLE49SR for its exceptional accuracy, boasting an angle error of less than 1 degree, and its remarkable immunity to external stray magnetic fields.

Infineon recently released a new angle sensor, the XENSIV TLE49SR, to determine precise automotive angular measurements. This can extend to applications such as chassis height, pedal position, throttle position, and steering angle sensors. Infineon hails the TLE49SR for its sharp accuracy, yielding an angle error of less than 1 degree, and its high stray field immunity. 

TLE49SR withstands stray magnetic fields of up to 8 mT. 

The Basic Architecture of the Angle Sensor

Infineon designed the TLE49SR around a differential Hall-based angle sensor, using spatially separated Hall cells to measure the magnetic field. These Hall cells include signal conditioning circuits within a single integrated circuit. The sensor supports three digital output interfaces: PWM, Single Edge Nibble Transmission (SENT), and Short PWM Code (SPC), conforming to the SAE J2716-2016 standard.

TLE49SR block diagram. 

The TLE49SR's architecture (datasheet linked) includes several key components: a Coordinate Rotation Digital Computer (CORDIC) algorithm for precise angle calculation, EEPROM for storing configuration data, such as zero angle and customer-specific IDs, and various diagnostic functions for operational reliability. The sensor can achieve a maximum intrinsic angle error of ±1 degree over its lifetime, demonstrating high precision.

Power, Performance, and Stray Field Immunity

The sensor operates within a wide voltage range, from -21 V to 26 V for supply voltage and -18 V to 19.5 V for interface voltage, with protection against high voltage and reverse polarity. The typical output resolution is 14 bits over a full 360 degree rotation, providing a fine granularity of angle measurement. The sensor also supports programmable measurement ranges and can handle angular speeds up to 10,000 rpm, with a total angle speed error of ±3%.

The TLE49SR offers low output noise, with a typical RMS noise level of 0.05 degrees at a 5-Hz filter setting, ensuring smooth and stable angle readings. The latency time for data transmission is tightly controlled, with a typical latency of 9.8 µs when using the lowest filter settings.

According to Infineon, what really sets the TLE49SR apart is its intrinsic stray field robustness, ranging from -8 mT to 8 mT for DC and -1.25 mT to 1.25 mT for AC. These specs allow the sensor to operate effectively even in the presence of external magnetic fields, making it useful for automotive environments where such conditions are common.  

Toward Vehicle Digitization

The TLE49SR answers the call for more automotive digitization by improving immunity to stray fields, heightening intrinsic accuracy, and decreasing angle error. The new angle sensor is built to high automotive packaging and safety standards, coming in a TDSO-8 package for surface mounting and complying with ISO 26262 as a “safety element out of context."