New stray-field robust position sensor with SPC interface

TDK Corporation has expanded of the Micronas masterHAL sensor family portfolio with the release of HAL 3970, a new stray-field robust 3D HAL position sensor. The sensor, ideal for automotive and industrial applications, offers high accuracy angular detection from 0-degree to 360-degree, linear position detection, and employs Short PWM Code frames (SPC) to transmit the calculated position information. SPC is an enhancement of the SENT protocol, according to SAE J2716. It allows data to be transmitted based on a trigger pulse sent by an external ECU, and it supports point-to-point connections as well as a single-wire bus mode with up to four sensors. Parameters, including unit time, trigger mode, frame format, slow channel format, rolling counter, and more, are readily configurable. For example, the device can be utilised for stray-field robust angle detection in steering-wheel position applications.

Each sensor within the sensor family is based on the patented 3D HAL pixel cell technology. The device employs a special array of Hall plates for high-accuracy measurement of vertical and horizontal magnetic-field components. As the device provides a sophisticated arrangement of these Hall plates, so the sensor detects angles up to 360 degrees and suppresses external magnetic stray fields. Just a simple two-pole magnet is needed to determine rotation angle. Ideally, the magnet ought to be placed above the sensitive area in an end-of-shaft configuration. The sensor also supports stray-field robust off-axis measurements.

Primary characteristics like gain and offset, reference position, etc. are able to be adjusted to the magnetic circuitry by programming the non-volatile memory. The device is defined as SEooC ASIL B-ready, according to ISO 26262. The device is offered in the eight-pin SOIC8 SMD package.