Automotive sensor designed for position detection in hybrid cars
A dual-die magnetic rotary position sensor with an I2C interface that enables the development of new space-saving designs in safety-critical automotive applications has been introduced by ams.
The AEC-Q100 grade 1 qualified AS5200L joins ams’ extensive portfolio of magnetic position sensors, with a feature set focused at electrified powertrain drive-by-wire control functions, such as shift-by-wire for both traditional stick and rotary shifters, and pedal applications.
ams’ traditional high performance and reliable position sensing technologies are reinforced in the AS5200L by the provision of dual dies. The stacked configuration of the dies means they may be paired with a single small target magnet while providing identical measurement outputs from each die. Separate package pins are provided for each die to prevent an electrical fault in the device from affecting both dies.
Like all ams magnetic position sensors, the AS5200L benefits from inherent immunity to stray magnetic fields and produces highly accurate and repeatable measurements even in noisy magnetic environments. The result is very reliable performance and reduced system cost, since there is no need for the shielding typically required by competitive magnetic position sensor ICs.
The AS5200L is housed in an MLF-16 package, with a space-saving footprint of just 5x5mm, and with exposed pads and wettable flanks for fast and simple board-level solder joint inspection.
The AS5200L is particularly well suited for automotive system designers seeking to implement robust, accurate rotary position sensing in vehicle electrification applications with tight space constraints, such as gear shifters and pedals, and in various other contactless potentiometer applications such as knobs and joysticks.
The provision of an I2C interface allows for easy programming of operating parameters by a host microcontroller without the need for a dedicated programmer. The AS5200L can provide its angle measurements via the I2C interface or as a PWM signal. Angle measurements are supplied in 12-bit resolution, and the maximum error attributable to inherent non-linearity is a maximum ±1°.
The AS5200L offers low power consumption in active and stand-by modes. A smart low power mode automatically reduces power consumption, resulting in average current of just 1.5mA when polling every 100ms.
The sensor measures rotation over a full 0-360° rotation by default. A smaller range can be set by programming a start and stop position into the chip’s One-Time Programmable (OTP) memory.
“The AS5200L is perfect for embedded safety-critical automotive applications in which high accuracy, redundancy and a very small footprint are of high priority,” said Thomas Mueller, Director of Marketing for position sensors at ams.
“The dual-die AS5200L with its redundant high resolution 12-bit I²C or PWM outputs, is ideally suited for shift-by-wire applications in hybrid, battery-powered and conventional vehicles. With its high performance and redundancy, the AS5200L can help automotive OEMs achieve up to ASIL D compliance at the system level.”