Simplified automotive electrification with high-speed inductive resolver for e-motors

Melexis has created a new inductive sensing IC intrinsically resistant to stray magnetic fields. The MLX90510 inductive interface IC allows a high-speed resolver minimising the ECU effort needed to get best-in-class accuracy under extreme mechanical and electrical conditions. The device is ideal for e-motor control, e-brake booster, and e-power steering applications with its excellent EMC capabilities.

The device provides excellent accuracy <+/-0.36-degrees at up to 240,000e-rpm. It is intended for demanding high-speed sensing applications with high accuracy, EMC and safety conditions.

“An efficient electric powertrain requires the synchronisation of the stator supply currents with the rotor position. This leads to optimal efficiency and torque characteristic control,” says Lorenzo Lugani, product manager Inductive Sensors at Melexis. “Thanks to the digital architecture and rugged design, automotive engineers take full advantage of the MLX90510 EMC robustness with minimal effort on the ECU side, resulting in module cost reduction.”

The device provides differential Sine and Cosine analog outputs based on a digital architecture. It includes Melexis’ patented tracking loop technology.

The device works together with a set of PCB based coils whose scalable design can be simply adapted to the number of pole-pairs of the motor. Supporting multiple sensing modes for on-axis (end-of-shaft) and off-axis (side-of-shaft or through-shaft) operation, the IC maximises pliancy in inductive coil designs to serve the most difficult mechanical constraints. With its overvoltage and reverse polarity protection (+/-24V on the supply and +/-18V on the outputs), the device offers exceptional robustness against electrical challenges. Also, the sensor is AEC-Q100 qualified for extended temperature operation from -40C to +160C. With full adherence to ISO 26262 ASIL C functional safety guidelines, the device supports up to ASIL D system-level integration.