Sensor design for high reliability

The ATS660LSB from Allegro MicroSystems is a digital differential gear-tooth sensor module designed to provide high levels of repeatability.

The ATS660LSB from Allegro MicroSystems is a digital differential gear-tooth sensor module designed to provide high levels of repeatability and timing accuracy in the most demanding automotive transmission applications.

The ATS660LSB incorporates self-calibration circuitry, that nulls out the effects of installation air gap and ambient temperature. There are magnet offsets to improve timing accuracy over large operating air gaps for target pitches varying from below 0.5 to over 1.2 teeth per diametric millimetre.

This self-calibration under power-up conditions keeps the performance optimised over the life of the sensor.

The integrated circuit within the sensor module incorporates a dual-element Hall-effect sensor and signal-processing circuitry that switches in response to differential magnetic signals created by the ferrous gear teeth. An open-collector output allows direct digital interfacing with no further signal processing required.

The circuitry contains a sophisticated digital circuit which eliminates the effects of magnet and system offsets, allowing true zero-speed operation. Analogue/digital and digital/analogue convertors 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.

This device is supplied in a package measuring 9mm in diameter ? 7mm in length.

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