Sensor improve automotive safety

Micronas HAL 2810 sensor can be used for angular measurements, such as in fuel-level sensing, and for linear movement, such as in seat-track position.

Micronas has released the first member of the HAL 28xy sensor family, the HAL 2810.

It is the first linear Hall-effect sensor to include a programmable microcontroller and a LIN bus 2.0 interface.

The device is a smart sensor, integrating the sensing element, all necessary compensation functions, digital signal processing as well as full LIN bus connectivity.

This reduces system cost and increases reliability.

The sensor is suitable to replace potentiometers in automotive applications.

It can be used for angular measurements, such as in fuel-level sensing, and for linear movement, such as in seat-track position.

In particular, the HAL 2810 is well-suited for passenger weight detection.

US Federal Motor Vehicle Safety Standard 208 requires passenger airbags that can sense the size and weight of front seat passengers and adjust accordingly.

The HAL 2810 measures the force on the seat attachment points and determines passenger weight based on these measurements.

"The HAL 2810 makes it possible to build up a complete LIN network with multiple sensors, offering a cost advantage compared to today's systems", says Peter Zimmermann, Market Manager Automotive at Micronas.

"Customers can save costs in the wiring harness as well as in the electronic architecture".

"In some applications a complete data acquisition and communication ECU can be eliminated".

The HAL 2810 is the first complete single-chip sensor solution integrating a LIN bus physical layer.

The sensor itself is extremely accurate.

It offers 12bit resolution and features both spinning-current and second-order temperature compensation over a range of -40 to +140C.

Included on-chip with the sensor is an 8bit microcontroller with boot ROM, EEPROM, RAM and the LIN bus slave interface.

The LIN bus interface is fully compatible with LIN Specification Package 2.0 and supports data rates of 10.4 and 20Kbit/s.

The boot ROM includes firmware to drive the LIN bus.

Micronas included the physical interface and overvoltage and reverse-voltage protection on all three pins, so the device can be connected directly to the bus.

The device is user-programmable via the LIN bus, so any LIN tool available on the market can be used to program the sensor.

Along with the HAL 28xy, Micronas offers an application kit containing a programming board, LabView programming software and the necessary source code.

Key application variables such as magnetic field range, sensitivity, offset and the temperature coefficients of sensitivity and offset can be adjusted by programming the nonvolatile memory.

The sample rate can be programmed from 27 to 54 samples per second.

Besides the 32bit LIN serial number, the HAL 2810 includes a user-programmable 12bit sensor ID register.

HAL 2810 samples are available in a TO-92UT package rated for operation from -40 to +140C.

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