Stray-Field Robust 3D Position Sensors with Analog/PWN/SENT Interfaces

HAL 3550 and HAR 3550 are a new generation of 2D position sensors from TDK-Micronas, developed for stray-field robust linear and angular position sensing and ISO 26262-compliant development. Building on the HAL/HAR/HAC 39xy family, HAL/HAR 3550 target mainstream applications that require a device with a core feature set and reduced configurability, without compromising functional safety or performance.

Both devices measure a full 360° angular range as well as linear movements and determine magnet position using TDK-Micronas 3D HAL technology. They provide a linear, ratiometric analog output with passive wire-break detection, and offer configurable PWM or SENT outputs. The SENT mode supports messages with or without a pause pulse, adheres to SAE J2716 rev. 4, and allows customization of parameters such as tick time and frame format; the PWM output supports frequencies from 0.1 kHz to 2 kHz. An additional switch output - derived from calculated position information or other points along the signal path - is available. Setpoint linearization can be selected as either 17 equidistant setpoints or 7 setpoints with variable spacing. An array of Hall plates suppresses external magnetic stray fields; only a simple two-pole magnet is required for rotation measurements, and off-axis measurements are also possible. The devices’ high sensitivity combined with low angular error enables the use of cost-efficient ferrite magnet material.

Major characteristics such as gain, offset and reference position can be adjusted to the magnetic circuitry by programming the nonvolatile memory. The sensors are defined as SEooC (Safety Element out of Context) ASIL C ready according to ISO 26262; dual-die variants can be integrated in automotive safety related systems up to ASIL D. The devices are specified for operation in an ambient temperature range of −40 °C to +150 °C. The HAL 3550 single die device is available in a very small eight-pin SOIC8 package. The HAR 3550 dual-die device is available in a small 16-pin TSSOP16 SMD package with full redundancy; each sensor contains two independent dies that are mechanically separated and electrically insulated.

License Note:
HAL 35xy and HAR 35xy use licenses of Fraunhofer Institute for Integrated Circuits IIS.