Programmable Hall sensor fits simply into industrial designs

October 14, 2014 // By Graham Prophet
MLX90290 is a monolithically integrated magnetic sensor IC, with amplifier, analogue output and internal compensation circuits all incorporated.

It converts magnetic flux into an analogue output and guarantees the critical functional parameters (such as sensitivity, offset and their respective thermal drift characteristics) to absolute levels, thus simplifying integration processes by removing the need for end-of-line calibration. This means that design engineers can confidently deliver high-performance position sensing solutions without extra end-of-line testing and validation, which can prove laborious and time consuming. They can simply buy off-the-shelf versions of the MLX90290 capable of satisfying their sensor requirements.

Standard versions of the MLX90290 when combined with MCU units allow fast and accurate rotary, linear or motor commutation applications to be realised. It also be applied to sense DC and AC current when combined with a ferrite toroid core.

Offered in variations for use with circuits operating at 3.3 VDC and 5 VDC bias, the MLX90290 enables position measurements with most common permanent magnets, such as AlNiCo and Ferrite. It is capable of compensating for the inherent thermal behaviour of the magnet. The device is offered in off-the-shelf variants for use with 500 ppm/°C materials for Alnico/Rare Earth type magnets and 2000 ppm/°C materials for low cost Ceramic/Ferrite magnets. In current sensing applications the thermal drift is targeted to 0 ppm/°C, so the IC has a thermal behaviour as flat as possible while achieving a high bandwidth.

High volume applications may be deemed suitable for a customised version. Here, filtering, sensitivity and thermal sensitivity drift may be fully optimised to meet a specific high volume application's performance requirements. The MLX90290 covers a -40°C to +150°C operational temperature range. It occupies a standard 3-pin SIP (UA) package or 3-pin SOT (TSOT23) package. The standard 1.27 mm pin-to-pin spacing version is the normal option or alternatively a 2.54 mm pin-to-pin spacing, lead-formed version can be specified. The wider pin-to-pin spacing is beneficial for welding or automated soldering in sensor modules. The part costs $0.75 (10,000)