TDK stray-field ASIL C ready hall-effect position sensor family

This new sensor family initially consists of two members, HAL 3020 and HAL 3021, and features differential and single-ended sine and cosine analogue outputs for standard angle calculation by an external microcontroller/ECU. HAL 3020 is the right choice for cost-effective applications like electric pumps or electric valves. For those types of applications, the sensor can easily be combined with TDK’s Micronas embedded motor controller portfolio for more precise and safe motor control. HAL 3021 suits for demanding high-speed sensing applications like electric power steering, e-motors (e-axle), electric brake boosters and electromechanical braking (EMB). Samples are available now, with the start of production planned for the first half of 2024.

HAL 302x sensors can measure a full 360° rotational angle by evaluating vertical magnetic-field components (BZ). While HAL 3020 uses an array of three horizontal Hall plates, HAL 3021 uses six. Both sensors are able to suppress external DC and AC magnetic stray fields (ISO 11452-8). By suppressing harmonic disturbances in the stimulation signals through device-internal calculations, a simple and cost-efficient two-pole ferrite magnet in an on-axis (end-of-shaft) configuration is sufficient to measure the absolute angular position. Thanks to the inherent stray-field robustness, the need for expensive magnetic shielding and the use of stronger target magnets is eliminated. This gives more flexibility in the design and production of next-generation electric motors to be used in hybrid and electric vehicles.

A key strength of HAL 3021 is that the device offers best-in-class robustness against static and dynamic mechanical misalignments, such as off-axis displacement, airgap variation and tilt. This ensures highly reliable and efficient field-oriented control of motors over their lifetime. To lower the load of the ECU, the sensor can compensate on-chip for the main sensor- and system-level non-ideals, like sine and cosine amplitude mismatch, offset errors, (absolute) 0-angle, and orthogonality errors.

HAL 302x is defined as Safety Element out of Context (SEooC) ASIL C ready according to ISO 26262, supporting system-level integration up to ASIL D. The sensor integrates various safety monitoring functions, which help to increase diagnostic coverage and simplify the external safety supervision on the ECU side. It operates in the junction temperature range from –40°C to +170°C. The sensor is available in the small eight-pin SOIC8 SMD package.

Main applications

• Brushless DC (BLDC) and permanent-magnet synchronous motor (PMSM) commutation in a safety-relevant environment
• Electric brake booster
• Electromechanical brake (EMB)
• Clutch and transmission actuators
• Starter/generator systems
• Electric pumps
• Electric valves

Main features and benefits

• High-speed 360° contactless angle measurement
• Robust against DC and AC magnetic stray fields (according to ISO 11452-8:2015)
• SEooC ASIL C ready according to ISO 26262:2018 to support Functional Safety applications (The device can be integrated in automotive safety-related systems up to ASIL D)
• EMC robust differential and single-ended SIN/COS analogue output signals
• On-chip calibration capability and integrated safety monitoring reduce effort on ECU side
• Wide customer programmable magnetic-field range between 5 and 250mT to adjust for different mechanical requirements and magnetic fields
• Operates from 3.0V up to 5.5V supply voltage
• Fast response time and high output bandwidth for applications up to 150,000rpm
• Operates from –40°C up to 170°C junction temperature
• Programming via the sensor’s output pin. Programmable at module level and no additional programming pin required
• Overvoltage and reverse-voltage protection