Allegro Micro unveils GMR sensors for HEV engine platforms

Allegro MicroSystems has released two new state-of-the-art giant magnetoresistance (GMR) crankshaft and camshaft sensors.

The ATS16951 (crankshaft) and ATS16351 (camshaft) sensors are able to provide manufacturers with a single-vendor solution suitable for hybrid vehicle engines, with use cases extending to two-wheelers, off-road vehicles, and application designs requiring extended air gap performance. Both sensors will help engine designers reduce system complexity, cost, and energy consumption—boosting efficiency and minimising carbon footprints.

Delivering 40% better edge repeatability and lower amounts of jitter compared to many existing products, the ATS16951 gives automakers new ways to increase fuel efficiency with higher-precision ignition and valvetrain timing. Its large air gap simplifies design-in, expands design margin and tolerance capability, and facilitates a wider range of sensor installation locations.

The ATS16351 True Power On State (TPOS) GMR camshaft sensor also improves both design-in flexibility and stray field immunity. It can be placed virtually anywhere, which is increasingly important as some hybrid engines now include four camshaft sensors.

Tight spaces often combine with high current transients, and engine designers need camshaft sensors that work seamlessly through the resulting stray fields. The ATS16351’s differential GMR architecture provides a level of immunity not currently available in legacy or competing solutions.

Both sensors include Allegro’s Target Profile Diagnostic feature, which makes it possible to assess a target during manufacturing and detect any subtle tooth anomalies before an engine is installed into a vehicle, helping to prevent potential warranty returns and increasing customer satisfaction.

The ATS16951 combines the electrical requirements and package size of legacy solutions with sensing location flexibility, making it a drop-in replacement for existing Hall-effect crankshaft sensors and simplifying design reuse. It includes a programmable pulse location between the centre or edge of the target feature, along with EEPROM-programmable performance optimisations and production traceability.

The ATS16351 is also highly programmable, allowing manufacturers to optimise the TPOS performance to the widest variety of engine designs.

Monolithic integration makes it possible for both sensors to achieve in-system performance and highly accurate speed and position detection. The fully integrated, single over-mould package is common to both devices and will help designers reduce design complexity and simplify the development process and allows suppliers to standardise production lines.

Enabling flexible design-in and system compensation, the three-pin single inline package (SIP) houses the IC, magnet, and EMC protection components. 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.

The ATS16951 was developed in accordance with ISO 26262 as a safety element out of context targeting ASIL B capability (pending assessment) for use in automotive safety-related systems when integrated and used in the manner prescribed in the applicable safety manual and datasheet.