Allegro launches new magnetic-position sensor for automotive applications

Allegro MicroSystems, Inc., a global provider in power and sensing solutions for motion control and energy-efficient systems, has announced the release of the A31315 sensor — the newest member of the 3DMAG family of rotary and linear magnetic-position sensor ICs for automotive and industrial applications.

The new 3DMAG sensors combine Allegro’s proven planar and vertical Hall-effect technologies to measure magnetic-field components along three axes (X, Y, Z), enabling true 3D-sensing capabilities with a wide magnetic dynamic range without saturation.

Continued advancements in advanced driver-assistance systems (ADAS) and autonomous driving systems present new performance and functional safety challenges for integrators. The A31315 sensor addresses these challenges by delivering the measurement accuracy and performance necessary to meet the stringent requirements of safety-critical automotive applications including steering, braking, transmission, and throttle systems.

The sensors’ flexible 3D Hall front-end and configurable signal processing architecture enable highly accurate, absolute linear position, and rotary position measurements up to 360° while easing system integration challenges by providing greater freedom in sensor placement.

Existing Allegro 3DMAG devices, such as the ALS31300 and ALS31313 sensors, also support 3D magnetometer applications in which all three magnetic components (B_X, B_Y, B_Z) are required to track complex magnetic movements.

“Building on Allegro’s decades of automotive magnetic-sensing innovation, the 3DMAG family expands our range of industry-leading position sensing solutions to include virtually any moving magnet system while offering the performance and functional safety capabilities required to enable the next generation of ADAS solutions,” said Scott Milne, business unit director at Allegro MicroSystems.

He added: “ADAS is a key growth engine for the automotive industry and our early position in this market — combined with a robust new product pipeline — provides our customers with the sensing solutions they need to accelerate the adoption of ADAS features in smart, autonomous vehicles.”

Benefits

Superior accuracy and on-chip diagnostics help improve driver, passenger, and public safety for autonomous and driver-assisted vehicles.
High-performance and flexibility across design placements and use cases simplifies bills of materials.
Low-power consumption and robust power management options help extend and optimize battery life.

Safety applications
Addressing the critical safety needs of autonomous driving systems and ADAS applications, the highly accurate A31315 position sensor contains advanced on-chip diagnostic features to ensure reliable, safe operation.

It supports rotary and linear-position sensing in a robust design with excellent native angle error over-temperature in any plane (<1.2° over the sensor’s full -40° ~ +150° C operating range).

As per the Following Safety Element out of Context (SEooC) functional safety guidelines, the A31315 sensor supports ASIL-B (single die) and ASIL-D (dual die) system-level integration in accordance with ISO 26262 and is automotive-qualified to AEC-Q100 Grade 0.

Trends
Emerging trends such as autonomous driving, vehicle electrification, and Industry 4.0 are creating new packaging, performance, and power constraints in many systems. The highly versatile 3DMAG sensors, including the new A31315, address these constraints by easing system integration while enabling customers to achieve stringent accuracy requirements.

The sensors’ wide range of programmable channel trim and linearization options can easily be adjusted to the magnetic circuitry to optimize for accuracy and manufacturing efficiency in end-of-line programming times for specific applications. These sensors also offer low-power consumption and flexible power management options, enabling battery life optimization in portable applications.

The 3DMAG sensors support flexible low-voltage programming through sensor outputs regardless of the interface (e.g., analog, SAE J2716 SENT, PWM, I2C), allowing direct programming by a microcontroller in embedded designs and simplifying the interface for end-of-line system calibration. This low-voltage programming option also opens up new system architectures with remote field-replaceable sensor module designs that can be programmed by the electronic-control unit (ECU).

The A31315 sensor is available as a single die in a compact SOIC-8 package, and as a fully redundant stacked dual die in a TSSOP-14 package for applications requiring redundancy or higher levels of measurement.

Unlike traditional side-by-side, dual-die configurations, Allegro’s stacked die construction closely aligns the sensing elements of both die, ensuring the measurement of nearly identical magnetic fields. This innovative design enables the dual-die A31315 sensor to offer superior channel-matching performance and tighter channel comparison thresholds common in fully redundant safety systems.