Magnetic Speed Sensors
Magnetic speed sensing built for precision, performance, and safety.
Backed by decades of algorithm expertise and proprietary signal processing, our speed sensor solutions ensure reliable operation—even in harsh environments with vibration, EMI, and air gap variations. With ASIL-ready and ASIL-compliant options and support for multiple interfaces, our portfolio is built for safety-critical systems and next-generation electric mobility.
Browse by category
Camshaft Sensor ICs
Allegro provides fully integrated camshaft position sensors for EMC protection and true power on state (TPOS).
Crankshaft Sensor ICs
Allegro’s high-performance crankshaft sensors offer excellent edge accuracy and flexible integration—optimized for 2-wheelers and essential for reliable start-stop engine control.
General Purpose Speed Sensors
Allegro’s general-purpose speed sensors bring proven automotive-grade performance to industrial applications.
Interface ICs
Allegro interface ICs for speed and pressure sensors deliver fast and accurate output ideal for various automotive and industrial applications. With integrated signal conditioning algorithms, Allegro interface ICs offer system simplification and advanced diagnostics for safety-critical systems.
Transmission Sensor ICs
Featuring advanced Hall and back-biased GMR technologies, our transmission sensors deliver exceptional vibration immunity, wide air gap performance, and stable output.
Wheel Speed Sensor ICs
Our GMR technology provides low jitter and high air gap over the widest installation tolerance, it also offers high accuracy for extremely precise wheel speed and position measurement.
Documentation & Resources
Application Note
Benefits of Dynamic Threshold Feature in ATS16351, GMR Back-Biased Speed Sensor IC
AN296257 - The Allegro ATS16351PSM [1] is a True-Power-On-State (TPOS) sensor providing the speed and position of a rotational ferromagnetic target.
Application Note
Guidelines for Measuring Vibration Immunity for Speed Sensors
AN296209 - This application note provides guidelines on how to measure a speed sensor’s response to vibration and analyzes the results to find the vibration immunity of speed sensors.
Application Note
Transmission Gear Tooth Sensing
AN296221 - In this application note learn how our industry-leading, time-proven algorithms included on our transmission ICs have been designed to handle the most stringent application conditions.
Application Note
Giant Magnetoresistance versus Hall-effect: A Comparison of Technologies for Speed Sensor Applications
Allegro MicroSystems giant magnetoresistance (GMR) effect technology offerings build on lessons learned from experience with Hall-effect devices to enable new options for speed sensing system design.
Application Note
Effect of Ring Magnet Dimensions on Differential Speed Sensor Performance
AN296251 - In this application note, we describe how ring magnet dimensions affect speed sensor performance is given.
Technical Article
The Future of Automotive Wheel Sensing with GMR
P0083 - With the rise of vehicle electrification, computerized control systems, and subsystem reliability monitoring, it has become essential for systems to have accurate rotational information for each wheel of the vehicle.
Application Note
Differential Hall-Effect Sensors: Safer and More Reliable for Two-Wheelers of the Future
AN296173 - The use of electronic controls for engine, transmission, and wheel speed in two- and three-wheeled vehicles is growing, particularly in developing nations. This trend is largely driven by mandates to improve air quality, fuel efficiency, and vehicle safety worldwide.
Application Note
System Advantages of High-Resolution Wheel Speed Sensing
AN296228 - With the vehicle market trending toward autonomous driving in the near future, the need for high resolution in the wheel speed sensor (WSS) business becomes essential. Allegro, with input from market leaders, has released the first high-resolution wheel speed sensor (HRWSS) that targets this demand.
Application Note
Magnetic Encoder Design for Electrical Motor Driving a Dual-Channel Differential Magnetic Speed Sensor IC
This application note describes how to use a Hall sensor device such as the Allegro ATS605LSG as an encoder in a system with a ferrous target, and gives target design recommendations to achieve outputs in quadrature and a 50% duty cycle for each output.
Application Note
Target Design for Back-Biased Hall Sensor IC ATS667LSG
In the following, the magnet designs are fixed by using an Allegro IC package with an integrated magnet.
Application Note
GMR Crankshaft Target Design Guidelines
AN296198 - This application note offers guidelines for designing an optimal target for crankshaft applications.
Application Note
Methods and Validation of Stray Magnetic Field Mitigation in Magnetic Speed Sensor ICs
AN296250 - This document provides an overview of the phenomena of stray magnetic fields, its various sources, solutions developed to minimize its effects, and product proposals tolerant to stray field perturbations.
Application Note
Target Design for Back Biased GMR Sensor IC ATS19580LSN
The ATS19580 employs GMR sensing technology in conjunction with SolidSpeed Digital architecture to transmit transmission gear sensing data to the system.
Application Note
Mechanical Shift of Switch Point
AN296243 - The mechanical shift of switch point is a specification that provides detail necessary to predict the location of an output edge with respect to the integrated circuit (IC) package and the target feature. This application note illustrates how to apply this specification.
Application Note
Target Design for Hall Transmission Sensors
AN296178 - This application note details the impact of multiple target design parameters on the maximum air gap achievable with Allegro’s ATS692LSH and ATS19520LSN transmission sensors, allowing for measurement of speed and direction of rotating targets.