Magnetic position sensor delivers high accuracy for ADAS applications

Allegro MicroSystems, Inc. has extended its 3DMAG family of rotary and linear magnetic position sensor ICs for automotive and industrial applications with the release of the A31315 sensor. The A31315 leverages the company’s planar and vertical Hall-effect technologies to measure magnetic field components along three axes (X, Y, Z). This enables true 3D sensing capabilities with a wide magnetic dynamic range without saturation, said the company.

Targeting advanced driver assistance systems (ADAS) and autonomous driving systems, the A31315 sensor provides the measurement accuracy and performance needed to meet the requirements of safety-critical automotive applications including steering, braking, transmission and throttle systems, said the company.

The 3DMAG family’s 3D Hall front-end and configurable signal processing architecture allow for highly accurate, absolute linear position and rotary position measurements up to 360°, and provides greater flexibility in sensor placement, according to the company. The sensors also offer a wide range of programmable channel trim and linearization options, which can be adjusted to the magnetic circuitry to optimize for both accuracy and manufacturing efficiency in end-of-line programming times for specific applications.

In addition, 3DMAG sensors support 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. The company said this low-voltage programming option opens up new system architectures with remote field-replaceable sensor module designs that can be programmed by the electronic control unit (ECU).

The A31315 position sensor includes advanced on-chip diagnostics, including the monitoring of internal and external fault conditions. It supports both rotary and linear position sensing with a native angle error over temperature in any plane at <1.2° over the sensor’s full -40°C  to 150°C operating range.

Functional block diagram of the A31315 (Image: Allegro MicroSystems)

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.

The A31315 sensor is available as a single die in a 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. Samples and evaluation kits are available.