Dual-Channel Linear Hall Sensor with PSI5 Interface for Automotive Applications
Infineon designed its newly released, dual-channel linear Hall sensor with PSI5 interface to meet the requirements of safety-critical automotive applications as well as industrial applications. (See simplified block diagram above). The XENSIV™ TLE4999I3 provides the means to fulfill the state-of-the-art functional safety requirements on a system level. The linear Hall sensor was developed in full compliance with ISO 26262.
Applications for the sensor include brake and acceleration pedals, valve or flap position sensing, steering torque sensing, high-speed applications, automotive and industrial safety, as well as any other use that requires precise and fast linear measurement.
The device uses two sensor elements included within one monolithic silicon design, thereby providing redundancy on one chip. The two diverse Hall sensor elements (main and sub) have internally separated signal paths within the chip. A plausibility check secures the high diagnostic coverage needed for premium functional safety compliant systems up to ASIL-D.
The TLE4999I3 supply architecture splits up into a digital supply and two analog supply circuits. This basic supply set-up separates the noise sensitive analog circuits from the fast switching digital portion.
Two analog supply domains are the basis for ensuring good separation of the internal voltage regulation for the main and sub Hall sensor elements.
Each sensor element has its own analog to digital converter, digital signal processor (DSP), and memory area to assure the maximum independence.
The two DSPs use their individual Hall signal, temperature-, and stress- information of the related sensor cell as well as the compensation parameters stored in the EEPROM to determine the two independent output values.
The implemented PSI5 communication interface supports a bitrate up to 189Kboud. Combining both sensor values within one output signal using the PSI5 v 2.1 protocol enables for a frame time of 500μs for both sensors' data.
The synchronous digital PSI5-compatible interface features a common 7-bit checksum. Several crosschecks of the TLE4999I3 on system level can be implemented using external safety mechanisms. This way it is possible to achieve functional safety compliant systems up to ASIL-D.
Features
- Two highly accurate redundant Hall measurement channels (main and sub) integrated on one chip
- Developed compliant to ISO 26262 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 channels independently programmable in EEPROM
- 16-bit user-configurable ID in EEPROM
- Supply voltage 5.5V to 7V
