Allegro Microsystems' A1468 is an optimized Hall effect sensing IC that provides a user-friendly solution for digital ring-magnet sensing, or when coupled with a magnet, ferromagnetic target sensing, in three-wire applications. The small device package can be easily assembled into applications for use in conjunction with a wide variety of target shapes and sizes. The integrated circuit incorporates dual Hall effect elements with a 2.2 mm spacing and signal processing that switches in response to differential magnetic signals created by ring magnet poles. The circuitry contains a sophisticated digital circuit to reduce system offsets, to calibrate the gain for air gap, independent switch points, and to achieve true zero-speed operation through peak-detecting algorithm. Signal optimization occurs at power-on through the combination of offset and gain adjust, and is maintained throughout the operating time with the use of a running-mode calibration. The running-mode calibration provides immunity to environmental effects such as micro-oscillations of the target or sudden air gap changes. The device is ideally suited to obtaining speed and duty-cycle information in ring-magnet based speed, position, and timing applications, such as in speedometers.