Speed sensor gives transmission designers more options

Combining advanced GMR technology with automotive grade algorithms and packaging technology, Allegro now offers a comprehensive transmission sensor portfolio that addresses the needs of today’s system developers and manufacturers, while taking advantage of the company’s 20 years of speed sensing expertise, application-specific experience, and technological advancement.

The device adds a speed-only protocol to the company’s recently released ATS19580 transmission speed and direction sensor IC. 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.

“As our newest single-chip GMR solution for gear tooth sensing, the ATS19480 optimises performance for emerging electric vehicle applications. It’s unique to the market, and outperforms competing technologies because of the high air gap and level of accuracy,” said Peter Wells, Magnetic Speed Business Unit Director at Allegro. “Our new speed sensor allows designers to do things that haven’t been possible until now. It can be placed virtually anywhere; transmissions can be smaller and lighter than ever before, which is especially important in applications where designers want the speed-only protocol. It’s a real game changer.”

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.

High integration and algorithms drive performance

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, and superior operation under harsh operating conditions can help to reduce failure rates - along with customer returns and warranty service claims.

Pricing and availability

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