Microchip's New High Speed Inductive Position Sensor
The LX34070 is expected to accelerate the move away from less accurate magnet-based solutions for EV motor position monitoring
Microchip Technology has announced the release of the LX34070 Inductive Position Sensor, this sensor has been purpose-built for EV motor control applications. It includes differential outputs, fast sample rates and features that make it functional-safety-ready for ISO 26262 compliance. Designers of motor control systems are rapidly replacing Hall Effect position sensors and older magnetic resolver solutions with inductive alternatives that eliminate expensive magnets and other heavy transformer-based structures so they can be integrated onto simple, compact printed circuit boards.

The LX34070 inductive position sensor solution offers numerous advantages compared to magnetic resolvers and Linear Voltage Differential Transducers (LVDTs), at a fraction of the cost. By using PCB traces rather than transformer-based magnetic windings and coil structures, the LX34070 device has negligible size and mass compared to alternatives that weigh as much as a pound. Accuracy is improved since the LX34070 does not depend on magnet strength, and the device improves robustness by actively rejecting stray magnetic fields. These and other features give designers greater flexibility over where they can place the thin, lightweight PCB-based LX34070 solution in their EV motor control designs.
PCB-based inductive position sensors use 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 that each secondary coil receives a different voltage whose ratio is used to calculate absolute position. Using these techniques, Microchip introduced its first high-volume inductive sensor for automotive and industrial applications over a decade ago and has many programs in volume production. The LX34070 now brings the same proven PCB materials, approaches and simplified, low-cost packaging to EV motor control and other applications that need its high-speed and low-latency benefits.
“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 at 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.”
Features of the LX34070 Inductive Positions Sensor include
- AEC-Q100 Grade 0 Certification
- Built-in Oscillator for Driving Primary Coil
- Two Independent Analog Channels With Demodulation
- Automatic Gain Control Maximizes Resolution over Large Target Air gaps Ranges
- 4.5V to 5.5V Input Range with Protection up to 18V
- Differential Output Buffers with Accurate Common-Mode Level and Protection Circuitry Against Shorts
- Detection of Faults at the Exciter Coil Pins and Receive Coil Pins
- Power Supply and Ground Loss Detection
- Calibration Through VIN or GPIO
More information on the LX34070 Inductive Positions Sensor can be found on the Microchip Web site at Microchip LX34070 product page
Note: The Microchip name and the Microchip logo are registered trademarks of Microchip Technology Incorporated in the U.S.A and other countries. All other trademarks mentioned herein are the property of their respective companies.
The company's Web site address is www.microchip.com
[Reprinted with kind permission from Microchip Corporation - Release Date, 15th June, 2022]