Infineon has introduced a magnetic sensor for micron-level motion measurement

Called the TLI5590-A6W, it has two internal TMR (tunnel magneto-resistive) Wheatstone bridges (see figure) spaced 500μm apart to provide sinusoidal and cosinusoidal voltages in the direction of operation as it moves relative to a long or circular magnet, whose poles change every 500μm.

The company says: "It qualifies for industrial and consumer applications under JEDEC JESD47K, and can achieve better than 10μm accuracy through the use of appropriate linear or rotary magnet encoders." "Channel matching is less than 5% over the entire magnetic input range of ±5mT.The operating range exceeds 1 to 5.5V, -40 to +125°C, and consumes 1mA at a nominal operating voltage of 3.3V - half the current consumption of each bridge.

The two bridges have different sensitivities: Bridge 1 (VP1 - VN1) is 12 to 25mV/V/mT (typically 18.5mV/V/mT) and Bridge 2 (VP2 - VN2) is 6 to 12.5mV/V/mT (typically 18.5mV/V/mT) 9mV/V/mT ).