Motor control system developers are rapidly adopting inductive alternatives to replace Hall-effect position sensors and older magnetic resolver solutions because these inductive alternatives do not require expensive magnets and other heavy transformer-based structures and can be integrated into Simple and compact printed circuit board (PCB). Microchip Technology Inc. announced the launch of the LX34070 IC designed for motor control applications, extending the world's broadest line of inductive position sensors into the electric vehicle motor control market. The new devices feature features such as differential outputs and fast sampling rates, and are functionally compliant to ISO 26262 in Automotive Safety Integrity Level C (ASIL-C) classification
"The LX34070 inductive position sensor enables lighter, smaller and more reliable motor control solutions that meet stringent safety requirements, reduce overall system cost, and Seamless and precise operation in noisy environments of automotive DC motors, high currents and solenoids. Designers can use the LX34070 to pair with other functionally safe Microchip devices to further simplify electric vehicle motor control designs. Related devices include 8-bit AVR® and PIC® microcontrollers, 32-bit microcontrollers, and dsPIC® digital signal controllers.”
Compared to magnetic resolvers and linear voltage differential sensors (LVDTs), the LX34070 inductive position sensor solution offers many advantages at a low cost. Using PCB traces rather than a transformer-based magnetic winding and coil structure, the size and weight of the LX34070 device is negligible compared to its one-pound counterpart. The LX34070 is not dependent on the strength of the magnetic field for improved accuracy, and also improves reliability and stability by actively rejecting stray magnetic fields. These features give designers more flexibility to use the thin and light PCB-based LX34070 solution in EV motor control designs.
PCB-based inductive position sensors use a primary coil to generate an AC magnetic field, coupled with two secondary coils. A small metallic target object disturbs the magnetic field, causing each secondary coil to receive a different voltage, the ratio of which is used to calculate absolute position. Microchip leveraged these technologies to introduce the first high-capacity inductive sensors for automotive and industrial applications more than a decade ago, and has numerous volume production projects. For electric vehicle motor control and other applications that require the benefits of high speed and low latency, the LX34070 brings the same proven PCB materials, methods, and simplified low-cost packaging.
