Allegro releases new GMR gear tooth speed sensor

Allegro MicroSystems has introduced a state-of-the-art giant magnetoresistance (GMR) speed sensor that measures the rotation of ferromagnetic gears.

The ATS19480 speed sensor IC provides a single-channel solution for hybrid and pure electric vehicle transmissions, with use cases extending to two-wheelers, off-road vehicles, and industrial application designs requiring speed-only information.

Combining advanced GMR technology with leading automotive grade algorithms and packaging technology, Allegro now offers a comprehensive transmission sensor portfolio.

The device adds a speed-only protocol to the company’s recently released ATS19580 transmission speed and direction sensor IC, allowing developers to achieve the highest levels of in-system capability and adaptability.

With an industry-leading air gap that’s 50% larger than existing options, it improves design-in flexibility, expands design margin and tolerance capability, and facilitates a wider range of sensor installation locations. This helps reduce system complexity, size, weight, cost, and energy consumption - boosting efficiency and minimising carbon footprints.

The ATS19480 sensor follows Allegro’s recent release of the dual-channel ATS19580 IC, the industry’s first fully-integrated GMR speed and direction sensor to offer superior vibration immunity in applications such as automotive transmissions. Both sensors complement Allegro’s ATS19420 and ATS19520 fully-integrated Hall-effect speed sensors, as well as the company’s family of front-biased Hall-effect and GMR products for magnetic target sensing.

Monolithic integration makes it possible for the ATS19480 sensor to achieve exceptional in-system performance and highly accurate speed detection. The fully integrated, single overmold package lessens design complexity and simplifies the development process.

Enabling flexible design-in and system compensation, the three-pin single inline package (SIP) houses the IC, magnet, and EMC protection. The precision assembly optimises IC-to-magnet positioning, as reduced tolerance stack between the IC and magnet increases sensor accuracy and leaves ample margin for in-application installation tolerance.

Advanced signal compensation eliminates flatline conditions caused by system dynamics, and differential sensing protects against common-mode stray fields. The ATS19480 includes integrated ASIL B diagnostics and certified safety design process for optional fault reporting.