Rotational speed sensor A1642 series

Hall effectdigital outputfor printed circuit boards

The A1642 is an optimized Hall-effect sensing integrated circuit that provides a user-friendly solution for true zero-speed digital ring-magnet sensing in two-wire applications. This small package can be easily assembled and used in conjunction with a wide variety of target shapes and sizes. The integrated circuit incorporates a dual-element Hall effect sensor 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-gapindependent switchpoints, and to achieve true zero-speed operation. 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 allows immunity to environmental effects such as micro-oscillations of the target or sudden air gap changes. The regulated current output is configured for two-wire applications and the sensor IC is ideally suited for obtaining speed and duty cycle information in ABS (antilock braking systems). The 1.5 mm spacing between the dual Hall elements is optimized for fine pitch ring-magnet-based configurations. For applications requiring sensing of rotating ferrous gears and targets, refer to the ATS642LSH series of products. The package is lead (Pb) free, with 100% matte tin leadframe plating.