The new A1232 from Allegro MicroSystems Europe is a Hall-effect speed and direction sensor IC with built-in hysteresis detection. This is a highly sensitive temperature-stable magnetic sensing device, ideal for use in ring magnet based speed and direction sensing systems in harsh automotive and industrial environments. It is the first device of its kind with the ability to detect when it powers up in the magnetic hysteresis band, reducing angle accuracy error that occur when edges are missed at start-up.
The Allegro A1232 includes dual Hall elements spaced 1.63mm apart that are photolithographically aligned to within 1µm. The precise spacing of the sensing elements eliminates a major manufacturing hurdle encountered when using fine-pitch ring magnets. The signals from the dual Hall elements are encoded into logic outputs representing the speed and direction of the target.