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
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
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
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.
Video
Allegro Differential Speed Sensor System Solutions
Seth Prentice, Strategic Marketing Manager for Allegro MicroSystems Speed Sensor IC group, discusses IC solutions for designing speed sensing applications including automotive transmissions, washing machine drum speeds, and fork lift positioning requiring reliable consistent output signals.
Technical Article
Crank Sensor IC for Stop-Start
This article describes start-stop operation and enabling Hall-effect integrated circuits, in particular the Allegro MicroSystems ATS694 and the previous generation ATS658, which are used in this application.
Application Note
EV Traction Motor Requirements and Speed Sensor Solutions
AN296226 - This paper explores the general requirement trends for speed and position sensors in traction motor systems, including high-speed capability, accuracy at startup, low-speed operation, immunity to vibration, EMC robustness, and safety.
Application Note
Impact of Magnetic Relative Permeability of Ferromagnetic Target on Back-Biased Sensor Output
This application note aims to describe the target relative magnetic permeability impact on Allegro back-biased magnetic sensor output.
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 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
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
Method for Mechanical Mounting Tolerance Compensation on Allegro Speed Sensors
AN296175 - Accuracy requirements for absolute mechanical edge detection on cam sensors and more generally on engine management speed sensors have noticeably increased with the need for power optimization and emissions control in car engines being sold today.
Application Note
System-Level Application Considerations for Magnetic Speed Sensors
AN296266 - The use of a noncontact, active, speed sensor integrated circuit (IC) greatly simplifies system design-in of a magnetic speed sensor. Although these ICs are designed to operate under a wide variety of system factors, the cautious automotive designer must contemplate certain more-subtle system considerations.