TDK launches dual-die HAR 3025 position sensor for steer-by-wire and EV traction motors

TDK has introduced the Micronas HAR 3025, a dual-die motor position sensor designed for safety-critical automotive and industrial applications.

The sensor is intended for electric power steering and x-by-wire motor control, including steer-by-wire actuators and brake-by-wire motors, and for high-voltage traction motor commutation.

The HAR 3025 stacks two independent dies in one 4 × 4 mm QFN24 package. The dies are aligned so that both occupy the same magnetic field and generate synchronous position signals, which enables a plausibility comparison at system level. Each die uses an array of six Hall plates and internal signal processing designed to suppress external magnetic stray fields in accordance with ISO 11452-8:2015. TDK says the stray-field suppression allows angular measurement without magnetic shielding or strong target magnets.

TDK says the HAR 3025 is ASIL D ready as a Safety Element out of Context (SEooC) under ISO 26262:2018 and that each die fulfills ASIL D metrics. If one die fails, the other remains fully operational and ASIL D compliant. Integrated diagnostics monitor the supply voltage, clock, temperature, Hall signal processing, EEPROM and configuration registers. When a fault is detected, the affected die’s outputs switch to high impedance, so the ECU can identify the fault using external pull-up or pull-down resistors.

The sensor provides redundant differential or single-ended sine and cosine analog outputs, and the microcontroller or ECU calculates the absolute angle. Gain, offset, zero angle, orthogonality and magnetic signal bandwidth can be programmed through the sensor’s output pin, so no additional programming pin is needed. Four selectable amplifier bandwidths from 4.6 kHz to 70.5 kHz allow designers to balance delay time against angular noise.

The HAR 3025 supports 360° angle measurement for motor commutation at up to 60,000 rpm. It operates from a 3.0 to 5.5 V supply over a junction temperature range of -40° C to 170° C, and the maximum ambient temperature is 150° C. Total angular error with static end-of-line calibration is 0.6° or less, and dynamic external compensation can reduce it to 0.1° or less.

Samples are available, and TDK plans to start production in the first half of 2027.

Source: TDK-Micronas