7 Linear position example with a 3D Hall-effect linear sensor

In linear motor transport systems with fast-moving payload carriers zipping by at 5m/s to 15 m/s, a 12-bit position resolution with latency <100µs and sample rates ≤8kHz is often sufficient, while multiple position sensors connect to a single MCU through a high-speed Serial Peripheral Interface (SPI) bus, as shown in Figure 3.

The TMAG5170 3D Hall-effect sensor provides three main advantages – accuracy, low latency and board placement flexibility. The sensitivity error drift across the full temperature range is less than 2.8%. A 10MHz SPI enables low latency. Additionally, onboard 3D sensing elements enable configurable XY, YZ or XZ sensing directions, enhancing flexibility when placing the sensor in relation to the magnet.

The Accurate Low-Latency Linear Position Sense Reference Design with Quad 3D Hall-Effect Sensors uses the TMAG5170 placed at 25mm intervals for precise, low-latency linear position sensing. A C2000™ MCU reads out the magnetic Z and X field data from all four TMAG5170 sensors for sample rates ≥8kHz, and calculates the moving magnet position with an error <0.15mm and latency <57.5µs.