Breaking Free from Rare Earths: Magnetic Position Sensors for a Smarter Automotive Future
Introduction: the rare earth challenge in automotive sensing
The automotive industry is electrifying at an unprecedented pace. Electric powertrains, advanced driver assistance systems, and drive by wire architectures are becoming standard. At the same time, the scarcity, cost, and geopolitical risk of rare earth elements increasingly challenge traditional sensor and system designs.
Rare earth materials have long been essential to magnetic sensors, particularly through high performance magnets such as neodymium and samarium cobalt. While powerful and compact, these materials are difficult to source, environmentally demanding to process, and subject to volatile global supply chains.
This tension raises a fundamental question for automotive engineers and system designers: how can precise, reliable position sensing be achieved while reducing dependence on rare earth materials?
Magnetic position sensors in modern vehicles
Magnetic position sensors are foundational to modern automotive and industrial applications. They enable accurate measurement of position, speed, angle, torque, and rotation, often in compact spaces and under harsh environmental conditions.
Wherever motion must be measured, sensing can typically be achieved either inductively or magnetically, each with its own strengths. Magnetic sensing, as supported by the ams OSRAM position sensor portfolio, enables ultra compact, automotive grade solutions that meet stringent functional safety and reliability requirements.
These sensors detect changes in magnetic fields and provide precise analog or digital signals via industry standard automotive communication protocols. They are widely used across powertrain, chassis, steering, and braking systems—particularly in emerging drive by wire applications.
Ferrite vs. Neodymium magnets: sensitivity and trade offs
Both ferrite magnets and neodymium magnets have their place in automotive systems, depending on performance needs, cost targets, and material constraints.
Neodymium magnets, which rely on rare earth elements such as neodymium, praseodymium, and dysprosium, generate strong magnetic fields in a compact form factor. This simplifies signal detection and improves robustness in low noise environments.
Ferrite magnets, by contrast, are rare earth free, cost effective, abundant, corrosion resistant, and heat tolerant, but they produce weaker magnetic fields. Using ferrites therefore places higher demands on sensor sensitivity and signal processing.
At the same time, increasing vehicle electrification introduces a second challenge: powerful electric motors draw currents in the hundreds of amperes, generating strong electromagnetic stray fields close to sensing locations.
As a result, modern magnetic sensors must achieve both high sensitivity to detect weaker ferrite based magnetic signals and strong stray field immunity to ensure reliable operation in noisy electromagnetic environments.
ams OSRAM smart sensor approach
ams OSRAM addresses this dual challenge through a smart sensor portfolio designed to reduce rare earth dependence without compromising performance.
Key characteristics include efficient operation with ferrite magnets, advanced signal processing that compensates for lower magnetic field strength, differential Hall based sensing that suppresses electromagnetic stray fields, and proven robustness in hundreds of millions of devices operating in real world automotive environments.
Hall based magnetic position sensors from ams OSRAM demonstrate high resilience to electromagnetic interference, helping maintain signal integrity even when strong stray fields are present. This creates a practical sweet spot between highly sensitive non Hall technologies—which are typically more susceptible to interference—and designs that rely on rare earth based neodymium magnets.
Beyond magnetics: inductive sensing and design support
In addition to magnetic sensing, the ams OSRAM portfolio also includes inductive position sensing technologies, which operate without magnets at all. These solutions are particularly well suited for harsh environments and high speed control applications.
To further support system design and optimization, ams OSRAM also offers the POS Simulator Tool, allowing engineers to simulate and compare ferrite based and rare earth based sensor setups early in the design process, helping identify the most suitable sensing architecture for a given application.
Conclusion: a more resilient and sustainable sensor future
The use of rare earth elements in automotive magnetic sensing highlights the complex trade offs faced in modern vehicle design. Achieving reliable sensitivity with weaker, ferrite based magnets must be balanced against the need for strong noise immunity in increasingly electrified and electromagnetically noisy environments.
By combining Hall based sensing, advanced signal processing, differential architectures, inductive alternatives, and design support tools, ams OSRAM enables high performance position sensing while supporting a reduction in rare earth material usage.
This smart sensor approach helps build more resilient supply chains, supports scalable electrification, and enables automotive innovation—without compromising accuracy, reliability, or performance.