In the automotive industry, magnetic sensors are an invisible yet indispensable technology that enables everything from turn signals to ignition timing.
There may be as many as 70 of these tiny sensors in your car, silently performing various assigned functions to allow you to move smoothly from destination A to destination B.
“Like many other semiconductor devices used to keep modern production and life running smoothly, users can’t see the magnetic sensor, but it plays a crucial role in many functions that we take for granted,” said Ricky Jackson, process development manager.
Massive applications
Magnetic sensors are ubiquitous, small in size, and inexpensive, and can be easily integrated onto chips with other circuitry. Therefore, they are widely used in a variety of applications. (For more information on magnetic sensors, please read the white paper.)
Magnetic sensing technology offers particularly significant advantages in robotics and factory automation. Due to the higher reliability and precision of magnetic sensors in detecting part position and speed, they are crucial for motion control. This advantage also allows robotic arms and other components to move smoothly and accurately, ensuring high-quality and safe manufacturing processes.
Besides automobiles, magnetic sensors are widely used in household appliances such as washing machines and microwave ovens to detect whether the machine's door is open or closed. Magnetic sensors are also widely used in medical devices; for example, when applied to hearing aids, they can detect whether the wearer is carrying a mobile phone and then switch to the appropriate mode to help the wearer hear incoming calls more clearly. Furthermore, they are often used for floor detection in elevators and for detecting whether handheld devices such as tablets or mobile phones are open or closed.
Working principle
Magnetic sensors work by converting magnetic fields into voltage or current information. Because the internal operation of the sensor and its external components do not require physical contact, magnetic sensors are ideal for reducing environmental pollution in automotive and industrial environments. They also reduce wear caused by friction between components, thereby lowering equipment maintenance costs.
Magnetic sensors have a wide variety of functions, but it is worth noting that two types of sensors can be widely integrated into other circuits: Hall effect sensors and fluxgate sensors.
Hall effect sensors are highly favored by manufacturers due to their reliable operation in various electromagnetic environments. Common applications include fuel gauges, primarily used to detect the float in the fuel tank, and brushless motors, where they detect rotor position and time current. When magnetic sensors are integrated with other circuits, the manufacturing process requires no special materials or treatments, helping to reduce design costs.
Compared to Hall effect sensors, fluxgate sensors are much more sensitive, capable of detecting extremely subtle changes in magnetic fields. Common applications of fluxgate sensors include electronic compasses for ships and aircraft, and instruments used by geologists to detect underground structures.
New Development
Texas Instruments (TI) offers a range of solutions related to integrated Hall effect or fluxgate sensors.
“We are developing a variety of magnetic induction technologies and integrating them into semiconductor processes to develop a variety of interesting new devices,” said Ross Eisenbeis, a systems engineer.
For engineers looking to use TI sensors in their chip designs, TI offers a wealth of on-chip features and support. A range of tools and software can assist engineers in creating new designs, and they can also exchange ideas and discuss best practices in our forum. Extensive online training programs can help engineers make the most of the features and advantages of TI magnetic sensors.
Ross stated, "We are developing a range of new technologies to help design engineers more easily achieve their performance and cost goals. At the same time, we can provide them with a wealth of user-friendly technical documentation. Our technical experts and IC designers are also continuously driving the development of these technologies."
