First Monolithically Integrated Linear Hall Sensor for ASIL D SystemsJune 16, 2019 by Paul Shepard
Infineon Technologies AG will launch a monolithically integrated linear Hall sensor which was developed entirely according to the safety standard ISO26262 for automotive applications: With just one device, the XENSIV™ TLE4999I3 enables the development of fault-tolerant systems that have to meet the highest level of functional safety (ASIL D).
Targeted applications include, for example, electric steering systems, electric throttle control systems, and pedal applications. Infineon will present the new sensor at the trade fair Sensor+Test.
ISO26262 requires a system to keep functioning even if a single fault occurs - for example if one of the components fails. Thus, the TLE4999I3 allows uninterrupted operation at system level. The device consists of a monolithic design with two independent Hall elements.
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Their signal paths are separate from each other. Internal control mechanisms carry out a plausibility check of the sensor data already within the chip. Furthermore, the new linear Hall sensor also provides extensive status information to the system.
In addition to functional safety, the TLE4999I3 also offers very high magnetic sensitivity with an error tolerance of less than 2 percent. The offset error drift, also an important parameter for magnetic sensors to determine the absolute position in a magnetic field, is maximum 100µT. This is just half that of comparable products. The values of these parameters apply across the entire temperature range and lifetime of the product.
With the TLE4999I3, two magnetic ranges of ±12.5mT and 25mT can be adjusted. These low values allow the use of relatively small and, consequently, inexpensive magnets.
The device features a PSI5 communication interface. Physically, this is a current interface, the advantages of which are a low wiring effort and an excellent electromagnetic performance. The TLE4999I3 is suitable for applications in which it is connected to the control unit over large distances: It supports cable lengths up to a distance of 12m.
Summary of features
- Two highly accurate redundant Hall measurement channels (main and sub) integrated on one chip.
- Developed compliant to ISO26262 for safety requirements rated up to ASIL D.
- PSI5 v2.1-compatible interface in synchronous mode with high speed P10P-400/4H protocol.
- Bi-directional interface for programming via fast SICI interface.
- 13-bit output signals, protected by CRC and rolling counters.
- Digital temperature and stress compensation.
- 3-pin leaded package for mounting in PCB-less modules.
- Operating junction temperature range -40°C to 150°C.
- Main and sub channel programmable independently in EEPROM.
- 16-bit user-configurable ID in EEPROM.
- Supply voltage 5.5 to 7 V.
The TLE4999I3 sensor comes in a PG-SSO-3 package, which allows a high degree of flexibility due to its small space requirement and shape. The device is qualified according to AECQ100, Grade 0 and can thus be used in applications with ambient temperatures of 150°C during average operational conditions.
The XENSIV TLE4999I3 is now available on the market.