Motion Sensors / Detectors / Transducers
Digital Speed Sensor features running mode calibration.
Press Release Summary:
Supplied in an SH package, ATS642LSH addresses critical requirements specific to ABS speed-sensing applications. This 2-wire, dual-element, Hall-effect sensor switches in response to differential magnetic signals from ferrous target and can handle airgap variations due to cornering events. Running mode calibration automatically adjusts for miscalibration without missing transition and maintains tight duty cycle over speed and temperature.
Original Press Release:
Allegro Microsystems, Inc. Introduces True Zero-Speed Digital Speed Sensor
ATS642LSH includes running mode calibration
Worcester, MA, Nov. 4, 2005 - Allegro MicroSystems, Inc. announces an innovative addition to its cutting-edge speed-sensing solutions, the ATS642LSH. This sensor addresses critical requirements specific to ABS speed-sensing applications. In particular, the sensitive ATS642 achieves far airgap requirements, as well as incorporates algorithms that eliminate the chance for false learning due to calibration on micro-vibrations at start-up. Additionally, the ATS642 is able to handle extreme airgap variations due to cornering events.
The ATS642 device is a two-wire, dual-element, Hall-effect sensor that switches in response to differential magnetic signals from a ferrous target.
The ATS642 centers the internally processed differential signal at power-up. It then immediately begins to track the differential signal and enters into the calibration phase. During calibration, the device effectively watches the amplitude of the signal. If the amplitude is sufficiently large, it reduces the gain to an optimal setting and centers the signal if required to maintain optimum switching. The ATS642 continues to monitor the signal and, once amplitude has been optimized, enters into running mode operation.
During running mode, the device follows the differential signal and looks for three consecutive peaks out of range. As such it assumes that it has miscalibrated, potentially on target micro-vibration. Should this event occur, the device will adjust the gain accordingly and, if necessary, readjust the signal to compensate for any offset. This is all accomplished without missing a transition and while keeping very tight duty cycle over speed and temperature. Furthermore, this algorithm makes the ATS642 relatively immune to micro-vibrations during start-up.
This sensor system is ideal for use in anti-lock braking systems and two-wire industrial speed sensor applications. Supplied in an SH package, the ATS642LSH will have a 16-week leadtime to market, and is priced at $2.06 for quantities of 10,000.
Allegro MicroSystems, Inc. is a supplier of advanced mixed-signal power semiconductors and Hall-effect sensors targeted toward the automotive, communications, computer/office automation, consumer and industrial markets. It maintains a leadership position in the integrated magnetic sensor and integrated motor driver product segments. With more than 2,000 employees, Allegro is headquartered in Worcester, MA. Further information about Allegro, including free samples of our products, can be found at www.allegromicro.com.
