The ATS645LSH is an optimized Hall effect sensing integrated circuit and magnet combination that provides a user-friendly solution for true zero-speed digital gear-tooth sensing in two-wire applications. The sensor consists of a single-shot molded plastic package that includes a samarium cobalt magnet, a pole piece, and a Hall effect IC that has been optimized to the magnetic circuit. This small package can be easily assembled and used in conjunction with a wide variety of gear 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 ferrous gear teeth. The circuitry contains a sophisticated digital circuit to eliminate magnet and system offsets and to achieve true zero speed operation (ref U.S. Patent 5,917,320). A-D and D-A converters are used to adjust the device gain at power up and to allow air gap independent switching.

The regulated current output is configured for two wire applications and the sensor is ideally suited for obtaining speed and duty cycle in ABS and transmission application gear-tooth-based configurations.