Allegro MicroSystems Inc. (Worcester, MA), a supplier of mixed-signal power semiconductors and hall-effect sensors, announced its new A1425 high-accuracy, analog speed sensor with integrated tracking capacitor and dual zero-crossing output signal. The A1425 is suitable for automotive crankshaft, speed-sensing applications using ring magnets.
The ac-coupled, differential sensor with on-chip capacitor is a true zero-crossing detector; the output switches precisely when the difference in magnetic field strength between the two Hall elements is zero. A dual-comparator scheme provides for accurate switching at the zero crossing on both the positive and negative going regions of the differential signal, while utilizing hysteresis to prevent false switching. The accurate switch-points are maintained over the entire automotive temperature range by an on-chip, temperature-compensation circuit.
Targeted at the industrial and automotive markets, the A1425 is priced at $1.21 in quantities of less than 100,000, and has a 22-week lead time to market.