AutomotiveElectronics

Direct-angle hall-effect sensors get ASIL-B status

TDK Corporation has upgraded its Micronas 3D HAL direct-angle Hall-effect sensor family, HAL 37xy (HAL 37xy, HAR 37xy, and HAC 37xy),* for automotive and industrial applications regarding functional safety aspects. All members of HAL 37xy are now defined as SEooC (Safety Element out of Context) ASIL B-ready, according to ISO 26262. HAL 37xy rotary position detection features are used in applications such as accelerator pedals, electronic throttle controls, rotary shifters (with push-function), and rear-axis steering systems. Furthermore, the sensors detect the linear position in applications like a clutch or brake pedals, transmission systems, cylinders, and valve position sensing. Relevant documentation, like safety manuals and FMEDA summary reports are available on request.

TDK enabled vertical Hall plates to integrate into the standard CMOS process through its 3D HAL technology. The process made it easier to evaluate the relative strength of the horizontal and vertical magnetic field components, which is key for excellent angular performance. In comparison, conventional planar Hall technology is only sensitive to the magnetic field orthogonal to the chip surface. TDK offers three different direct-angle sensor variants with the HAL 37xy sensors: the proven HAL 37xy sensor family, a version with redundancy function via two integrated Hall sensor dies (HAR 37xy), and a version with integrated capacitors (HAC 37xy).

The robust direct angle sensor family HAL 37xy offers outstanding temperature stability, high resistance against air gap variations and magnet aging, a range of diagnostic functions, and very effective protection circuitry. HAR 37xy, the dual-die version of the HAL 37xy family, provides full redundancy from two independent dies stacked in a single package that is bonded on separate sides. The stacked-die architecture ensures that both die to occupy the same magnetic-field position, thus generating synchronous measurement outputs. Redundant sensor solutions in a single package reduce system costs while increasing the reliability of the system through smaller PCBs and fewer solder joints. HAC 37xy integrates a chip from the HAL 37xy sensor family and two capacitors up to 330 nF in a three-lead TO package for an ESD immunity of up to 8 kV. The pins of the package can be welded or soldered directly to a lead frame eliminating the need for a printed circuit board (PCB) and reducing the total system size and cost.

The ASIL-B upgrade enables the TDK sensor customers’ base to use this product family in applications with functional safety demands. It makes the HAL 37xy mature product line fit for future customer applications.

HAL 37xy family’s production is already ongoing; samples are available at any time.

You may also like: