AutomotiveElectronics

Gear tooth speed sensor employs magnetoresistance technology

Allegro MicroSystems, Inc. has introduced a new, 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 that’s ideal 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 cutting-edge, comprehensive transmission sensor portfolio that addresses the needs of today’s system developers and manufacturers, while leveraging the company’s 20 years of speed-sensing expertise, application-specific experience, and technological advancement.

The ATS19480 adds a speed-only protocol to the company’s recently released ATS19580 transmission speed and direction sensor IC, setting a new standard for speed sensing and 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 minimizing 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 optimizes IC-to-magnet positioning, as a 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 a certified safety design process for optional fault reporting, and superior operation under harsh operating conditions can help to reduce failure rates—along with customer returns and warranty service claims.

The back-biased ATS19480 speed sensor IC is available now in a lead (Pb)-free, 3-pin SIP package (suffix SN) with tin-lead frame plating.