Invisible but indispensable: The future of sensing is magnetic

Myriad usesThe next time you get in your car, consider an invisible but crucial technology that makes everything from turn signals to ignition timing possible: magnetic sensors.

You may have up to 70 of these little-heralded devices in your vehicle, quietly doing their part in helping you get from point A to point B.

"Like so many other semiconductor devices that make the modern world go round, magnetic sensors are invisible to end users but indispensable for many of the functions that we have come to take for granted," said Ricky Jackson, a process development manager.

Myriad uses

Magnetic sensors have become ubiquitous because of their small size and affordability, which enables easy integration with other circuitry on a chip. (You can learn more about magnetic sensors by reading our white paper.)

The technology is particularly useful in robotics and factory automation. Because the sensors provide greater reliability and precision for detecting the position and speed of moving parts, they are often critical for motion control, where robotic arms and other parts must move smoothly and precisely to ensure high-quality manufacturing and safety.

In addition to your car, magnetic sensors are present in home appliances such as washing machines and microwave ovens -- to sense whether a door is open or closed -- and in medical devices. For example, in hearing aids they detect the presence of a mobile phone and then change modes so the wearer can hear the call more clearly. You'll also find them detecting floors in elevators and turning on and off handheld devices such as tablets and cell phones.

How they work

Magnetic sensors operate by converting magnetic fields into voltage or current information. Since the inner workings of the sensor and an external part require no actual contact, they are ideal for less-than-pristine environments such as automobiles and industrial settings. They also reduce wear and tear on parts that might otherwise rub against each other, meaning that less maintenance is needed for equipment.

Magnetic sensors function in a variety of ways, but two types in particular lend themselves to integration with other circuits: Hall effect sensors and fluxgate sensors.

Hall effect sensors are popular among manufacturers because of their ability to operate reliably in a wide range of electromagnetic environments. Common applications include fuel gauges, where they detect the presence of a float in a fuel tank, and brushless motors, where they detect the position of the rotor in order to time the flow of current. When integrated with other circuitry, they require no special materials or treatment during manufacturing, which helps keep costs low.

Fluxgate sensors are more sensitive than Hall effect sensors and can detect much smaller changes in magnetic fields. They are used in applications ranging from electronic compasses for ships and aircraft to equipment used by geologists to detect underground structures.

New possibilities

We offer a range of solutions that integrate either Hall effect or fluxgate magnetic sensors.

"We’re developing an assortment of magnetic sensing technologies and integrating them into our semiconductor processes, enabling all sorts of interesting new device possibilities,” said Ross Eisenbeis, a systems engineer.

A variety of integration capabilities for on-chip functions, as well as support, is available for engineers who want to use our sensors in their chip designs. A range of tools and software provides a starting point to aid engineers in creating new designs, while our forums enable engineers to exchange ideas and best practices. A variety of online training programs can help them get the most out of our products.

“We’re creating technologies that ultimately make things easier for design engineers, in terms of both performance and cost goals. Great documentation and ease of use is also crucial,” Ross said. “Our process technology experts and IC designers keep pushing forward.”