Nowadays, the market demand for magnetic field sensors is increasing, especially for the requirements of stray magnetic field compensation, which brings new challenges to the design of magnetic sensors. At the same time, the need for autonomous driving, higher functional safety requirements, and the growing demand for digital interfaces has called for a new type of sensor with more features and greater flexibility. With this in mind, TDK introduces a unique 3D Hall-effect position sensor with stray magnetic field compensation and a flexible design.

Magnetic field sensors, especially Hall effect sensors, are widely used in industrial and automotive electronics. The main reason is that they cost-effectively integrate many additional features. In recent years, in addition to Hall-effect switches and one-dimensional sensors, more and more 2D/3D sensors have been designed and applied to advanced automotive electronics. These sensors must meet the growing demand.

For example, ISO 26262 has higher safety requirements for autonomous driving applications. In addition, Hyundai has more and more highly controlled actuators that must provide digital interfaces (such as SENT, SPI and PSI5), low power modes and 3D capabilities.

TDK introduces a unique 3D Hall effect position sensor with stray magnetic field compensation

Figure 1: New Micronas HAL® 39xy Hall-effect position sensor series with multiple measurement modes with active stray magnetic field compensation

The growing challenge of stray magnetic fields

The requirement for stray magnetic fields is a major challenge, especially for magnetic field sensors. The electric and power lines of hybrid electric vehicles (HEV) and pure electric vehicles (BEV) carry high currents and generate magnetic fields that can interfere with magnetic field sensors. A modern Hall effect sensor must provide robust stray magnetic field immunity in accordance with the latest ISO 11452-8 and related OEM requirements. In the past, people used the magnetic field strength of magnets in the application to balance the external interference field. However, due to cost considerations, magnet structure design is becoming more and more miniaturized, which makes active stray magnetic field compensation necessary for magnetic field sensors.

HAL® 39xy position sensor series, unique stray magnetic field concept

The new Micronas HAL® 39xy position sensor family has successfully achieved all of these challenging goals. The Hall sensor not only accurately measures the magnetic field, but also has low sensitivity to disturbing magnetic fields. Their unique stray magnetic field concept is based on vertical and horizontal Hall plate arrays. At the heart of the sensor is the patented 3D Hall pixel unit. The highly flexible sensor array allows design engineers to choose the best stray magnetic field concept for different measurement tasks.

The HAL 39xy series has four different measurement modes:
• Linear position detection with stray magnetic field compensation
• Rotating 360¡ã angle detection with stray magnetic field compensation
• Rotating 180¡ã angle detection with stray magnetic field compensation
• True 3D magnetic field detection (Bx, By and Bz)

Each mode uses a different combination of Hall plates to ensure optimum performance in each mode. The HAL39xy is the only solution on the market that integrates four modes into a single device, giving customers a distinct advantage: they can meet different applications with just one device, without the need for multiple different hardware versions.

Customizable and fast-forming flexible architecture
The HAL 39xy series features a flexible architecture that supports different configurations. It has powerful DSP and embedded microcontrollers, of which DSP is mainly responsible for fast signal processing (angle calculation, compensation, etc.), and the microcontroller is responsible for overall scheduling, interface configuration and monitoring of functional safety related tasks. Develop custom firmware for use with both modules. Combined with a flexible Hall front end, this allows customers to implement a variety of new applications, such as custom signal processing or support for new interface standards. The HAL 39xy's innovative architecture makes it easier for customers to apply rapid prototyping technology to develop new solutions while quickly adapting to new interface changes such as SENT and PSI5.
TDK introduces a unique 3D Hall effect position sensor with stray magnetic field compensation

Figure 2: In addition to the patented Hall cell array, the Micronas HAL® 39xy Hall-effect position sensor family features powerful DSP and embedded microcontrollers, both with configurable firmware

A unique solution for a wide range of automotive and industrial applications

With the new Micronas HAL 39x series, TDK now offers a unique solution that meets the latest requirements for magnetic field position sensors. These sensors are suitable for a wide range of automotive and industrial applications, including:
• All types of valves and actuators (eg cooling valves, EGR, turbocharged actuators)
• Selector and gearbox
• Pedal position detection
• Position detection of the gearbox gearbox
• Steering angle detection
• Chassis position detection

TDK will be the first to release HAL 3900 (SPI), HAL 3930 (SENT/PWM) and HAL3980 (PSI5) sensors in SOCI8 package. Engineering design samples are now ready to begin booking. More package types and other interface types will be available in the future.