The ATS665LSG is an optimized Hall IC/magnet configuration packaged as a module that provides a user-friendly solution for digital gear-tooth-sensing applications. This digital differential Hall-effect sensor is the choice when repeatability and timing accuracy count. The module incorporates patented self-calibration circuitry 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 automotive transmission applications. The self-calibration at power up keeps the performance optimized over the life of the sensor. The ATS665LSG has an open-collector output for direct digital interfacing with no further signal processing required.

The integrated circuit incorporates a dual-element Hall-effect sensor and signal processing that switches in response to differential magnetic signals created by a ferrous target. The circuitry contains a sophisticated digital circuit to eliminate the detrimental effects of magnet and system offsets and to achieve true zero-speed operation. Digital processing of the analog signal provides zero-speed performance independent of air gap and also dynamic adaptation of device performance to the typical operating conditions found in automotive applications (reduced vibration sensitivity). High-resolution, peakdetecting DACs are used to set the switching thresholds; hysteresis reduces the negative effects of any anomalies in the magnetic signal associated with the target.