Family of inductive position sensors includes ISO 26262-compliant solution

22-06-2022 | Microchip Technology | Automotive & Transport

Microchip Technology Inc now offers the LX34070 IC that has been purpose-built for EV motor control applications. It incorporates differential outputs, fast sample rates and features that make it functional-safety-ready for ISO 26262 compliance in the Automotive Safety Integrity Level–C (ASIL–C) classification.

“The LX34070 inductive position sensor enables lighter, smaller, more reliable motor control solutions that meet stringent safety requirements, reduce overall system costs, and can operate seamlessly and precisely in the noisy environment of an automobile’s DC motors, high currents and solenoids,” said Fanie Duvenhage, vice president of Microchip’s mixed-signal and linear analog business unit. “Designers can use the LX34070 to further streamline EV motor control designs by pairing it with other functional-safety-ready Microchip devices, including our 8-bit AVR and PIC microcontrollers, our 32-bit microcontrollers, and our dsPIC digital signal controllers.”

The inductive position sensor solution provides many advantages compared to magnetic resolvers and LVDTs, at a fraction of the cost. By employing PCB traces rather than transformer-based magnetic windings and coil structures, the device has negligible size and mass compared to alternatives that weigh as much as a pound. Accuracy is bettered since the device does not depend on magnet strength, and the device enhances robustness by actively rejecting stray magnetic fields. These and other features give designers better flexibility over where they can place the thin, lightweight PCB-based solution in their EV motor control designs.

PCB-based inductive position sensors utilise a primary coil to generate an AC magnetic field that couples with two secondary coils. A small metal target object disturbs the magnetic field, so each secondary coil acquires a different voltage whose ratio is employed to calculate absolute position.

The device now brings the same proven PCB materials, approaches and simplified, low-cost packaging to EV motor control and other applications that require its high-speed and low-latency benefits.

By Natasha Shek