Speed sensor IC is robust for two-wheeled vehicle applications

Designed for position and timing applications, such as speedometers and tachometers for engine control in two-wheeled vehicles, the A17301 is a Hall-effect sensor IC from Allegro Microsystems Europe.

It integrates EMC components into a small SIP to provide a robust solution for digital ring-magnet sensing or ferromagnetic target sensing when coupled with a back-biasing magnet, says Allegro. It eliminates the need for external filter capacitors while improving reliability and reducing the cost of a final sensor assembly. The IC incorporates dual Hall-effect elements with 2.2mm spacing and signal processing that switches in response to differential magnetic signals.

Allegro’s differential architecture inherently avoids the flatline and chatter issues that single Hall element solutions often face, explained Bob Fortin, vice president of Allegro’s sensor business unit. As a result it can be used for obtaining speed and duty cycle information for position and timing applications.

The A17301 contains digital circuits to reduce system offsets, to calibrate the gain for airgap independent switch points, and to achieve true zero-speed operation. Running mode recalibration provides immunity to environmental effects such as micro-oscillations of the target or sudden air gap changes. The use of a digital peak detector for output switching control ensures that the input signal is continuously and accurately tracked, regardless of the amount of signal shift between output edges.

Allegro offers the A17301 in a three-pin SIP (suffix UC). The package is lead (Pb) free with 100 per cent matt-tin lead frame plating and an operating ambient temperature range of -40 to +160 degrees C.

Allegro MicroSystems develops power and sensing semiconductors. Its products serve high-growth applications within the automotive market, with additional focus on industrial and consumer/computing solutions. Allegro is headquartered in Manchester, New Hampshire (USA) with design, applications, and sales support centers located worldwide.

Allegro MicroSystems Europe is headquartered in Chertsey, United Kingdom, and is the European sales and marketing operation. It operates a network of representatives and distributors throughout Europe. Allegro has a technical and marketing centre in Heidelberg in Germany, an engineering design centre in Edinburgh in Scotland and a technical and marketing centre in Annecy in France.