Allegro MicroSystems Europe has announced a new package for its wheel speed sensor product family. The package includes an optimized Hall-effect integrated circuit (IC), a rare-earth pellet, and a high-temperature ceramic capacitor in a single overmolded package.The fully integrated solution reduces the need for external EMC protection and the integration of a magnetic circuit, thus reducing manufacturing complexity. Allegro's ATS688LSN provides an easy-to-use solution for true zero-speed digital gear tooth detection in two-wire applications, such as two-wheel or automotive braking systems.
The unique integrated circuit and magnet combination incorporates a dual-element Hall-effect sensor IC and signal processing circuitry that switches in response to differential magnetic signals created by a rotating ferromagnetic target. The device contains sophisticated compensation circuitry to eliminate magnetic and system offsets. Digital tracking of the analog signal is used to achieve true zero-speed operation. Advanced calibration algorithms are used to adjust the device's gain and offset during power-up, resulting in independent switching points at air intervals, which greatly improves output accuracy and mitigates the effect of system anomalies such as target vibration and abrupt air interval changes. The regulated current output is configured for two-wire operation.
The ATS688LSN is supplied in a lead-free (Pb) 3-pin back-biased SIP package (SN suffix) with tin-plated lead.
