Allegro's new sensors combine the company's Vertical Hall Effect (VHT) technology with cutting-edge Tunneling Magnetoresistance (TMR) technology in a single sensor package. These innovative angle sensors are the first of their kind to feature this technological combination in a single package. This VHT+TMR offering is a superior heterogeneous redundant sensor solution and is an essential step toward enabling the reliability required for advanced levels of vehicle automation.
Future automated and autonomous vehicles require advanced electric power steering (EPS) systems with precise motor control capabilities, as well as brake-by-wire or electromechanical systems with fast response times. Current systems typically use giant magnetoresistance (GMR) or Hall-effect sensors. Compared to GMR equivalents, Allegro's innovative silicon-based TMR technology offers improved resolution and accuracy, providing up to eight times greater sensitivity. When compared to traditional Hall-effect sensors, the resolution improvement is even more pronounced.
The safe operation of a vehicle requires the highest level of diagnostic coverage for its safety-critical systems. The Allegro VHT included in the new A33110 and A33115 enables precise safety checks, including low-field and missing magnet detection. These high-resolution sensors comply with ASIL D standards, and their heterogeneous redundancy reduces the likelihood of dependent failures by leveraging the best of both TMR and VHT technologies.
“As full autonomy moves closer to becoming a reality, automakers and Tier 1 suppliers are looking for position sensors that provide the highest accuracy and safety while reducing system space and cost,” said Scott Milne, Director of the Position Sensors Business Line at Allegro. “By integrating vertical Hall and TMR elements into a single package, Allegro’s new sensor lineup enables customers to meet those needs with a sensor that provides high resolution and heterogeneous redundancy along with built-in diagnostics. There’s nothing else like them on the market, and we believe they represent a significant step forward for the industry.”.
Allegro's A33110 and A33115 sensors provide magnetic angle detection via primary (TMR) and secondary (vertical Hall) transducers, each processed by two independent channels, each with its own temperature regulator and sensor. This unique configuration enables the high levels of safety and diagnostic coverage required for automated driving, including on-chip channel-to-channel angle comparison and independent processing on digital signal paths, without sharing digital resources. The advanced algorithms in the A33110 and A33115 provide the fast response time, independent gain/offset correction, angle calculation, and linearization capabilities demanded by safety-critical ADAS applications. The A33115 also includes a lap counter that tracks movement in 90-degree increments and a low-power mode with a user-programmable duty cycle that reduces power consumption when the IC is in the off position.
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