Cutting-edge Magnetic Gradiometer Revolutionizes Precision Measurement

Infineon, a leading semiconductor manufacturer, has recently unveiled a groundbreaking magnetic sensor designed for precise micron-level movement measurement. Known as the TLI5590-A6W, this sensor incorporates two TMR (tunnel magneto-resistance) Wheatstone bridges, positioned 500μm apart. These bridges generate sine and cosine voltages when moved in relation to long or circular magnets, which alternate their poles every 500μm in the working direction.

The TLI5590-A6W has been specifically engineered to meet the rigorous standards of both industrial and consumer applications, as outlined by JEDEC JESD47K. Infineon claims that this sensor can achieve an impressive accuracy of better than 10µm, provided that a suitable linear or rotary magnet encoder is utilized. Furthermore, the channel matching of the TLI5590-A6W is less than 5% across its entire magnetic input range of ±5mT.

Operating within a wide range of 1 to 5.5V and temperatures ranging from -40 to +125°C, the TLI5590-A6W consumes a mere 1mA at its nominal working voltage of 3.3V. Each of the two bridges draws half of this current. It is worth noting that the two bridges exhibit different sensitivities. Bridge 1 (VP1 - VN1) has a sensitivity range of 12 to 25mV/V/mT (typically 18.5mV/V/mT), while Bridge 2 (VP2 - VN2) has a sensitivity range of 6 to 12.5mV/V/mT (typically 9mV/V/mT). Infineon has been asked to explain the reason behind this discrepancy.

The TLI5590-A6W boasts a temperature coefficient of differential output voltage amplitude of typically -0.01%/K. Additionally, the differential offset is ±10mV/V, with a maximum temperature coefficient of ±10μV/V/K (typically 0μV/V/K). When considering a nominal movement of 1mm (equivalent to one magnetic cycle), the residual angular error is typically ±2° (±4.1° max) between 1.5 and 5mT. This error improves to ±0.8° (±2.5° max) at or below 1.5mT.

The TLI5590-A6W is designed to be directly connected to the analog inputs of a microcontroller. To ensure optimal performance, Infineon recommends the use of equal capacitors to 0V on each line, forming low-pass filters. "The value for the buffer capacitor has to be adjusted according to the speed of the magnetic input signal," explained Infineon. "This filter limits the bandwidth of the circuit but improves noise performance." With four 5nF capacitors connected, the bandwidth is approximately 5kHz.

Measuring a mere 1 x 1.3 x 0.6mm, the TLI5590-A6W is packaged in a wafer-level BGA package. This compact size makes it suitable for a wide range of applications, including sensing zoom lens position in cameras, as well as various industrial and medical uses.

For more information about the TLI5590-A6W, please visit the TLI5590-A6W product page.