The ATS660LSB is an ideal gear-tooth sensor solution for uniform teeth targets as found in today's demanding transmission applications. This digital differential Hall-effect sensor is the choice when repeatability and timing accuracy count. The ATS660LSB incorporates patented self-calibration circuitry (U.S. Pat. 5,917,320) that nulls out the effects of installation air gap, ambient temperature, and magnet offsets to provide superior timing accuracy with symmetrical targets over large operating air gaps -- typical of targets used in speed-sensing applications (pitches varying from below 0.5 to over 1.2 teeth per diametric millimeter). The self-calibration at power up keeps the performance optimized over the life of the sensor. The ATS660LSB has an opencollector output for direct digital interfacing with no further signal processing required. This device is available in a small 9-mm diameter by 7-mm long package for optimal manufacturing. The integrated circuit incorporates a dual-element Hall-effect sensor and signal processing that switches in response to differential magnetic signals created by the ferrous gear teeth. The circuitry contains a sophisticated digital circuit to eliminate magnet and system offsets and to achieve true zero-speed operation . D-to-A converters are used to adjust the device gain at power on and to allow air-gap independent switching, which greatly reduces vibration sensitivity of the device.