2D Hall Sensors Eye Motor/Encoder Apps

Allegro MicroSystems’ family of 2D Hall-Effect Latch ICs feature both vertical and planar Hall elements. The APS12625 and APS12626 enable reduced system size and bill-of-materials (BOM) cost along with an increase in performance and flexibility due to two-dimensional (2D) sensing. They were developed in accordance with ISO 26262 and qualified per AEC-Q100, making them suitable for automotive and other safety systems.


The APS12625 features Speed and Direction outputs whereas the APS12626 has quadrature (Channel A and B) outputs. An optional feature allows the host system to restore the previous state of the sensor after a power-cycle. This reduces the potential accumulation of lost counts in intelligent motion applications such as window lifts with anti-pinch requirements.


Each IC contains a pair of sensor ICs that are orthogonal to one another and provide 90° of phase separation between channels that is independent of magnet pole spacing and air gap. They are both available in each of three combinations of vertical and planar Hall elements (XY, ZX, and ZY). Virtually any orientation between the sensor IC and the ring magnet can be accommodated, and the ring magnet pitch can be changed without losing quadrature.


The monolithic devices each include three Hall plates (one planar, two vertical), a multiplexer, a small-signal amplifier, chopper stabilization, a Schmitt trigger, and two NMOS output transistors. They operate from 2.8 to 5.5 V and up to 175°C junction temperature. (See the device datasheet for details.) Each tiny SOT23-5 device replaces a pair of conventional Hall-effect latch ICs, meaning that redundant sensing for safety applications can be accomplished in virtually the same space as non-redundant implementations using legacy technology.


Pricing is:


APS12625LLHA - $0.39 each/3,000

APS12626LLHA - $0.39 each/3,000

APS12625LLHA with power-on hysteresis override (“-P” option) - $0.41 each/3,000

APS12626LLHA with power-on hysteresis override (“-P” option) - $0.41 each/3,000


Need more enlightenment? Peruse the APS12625 and APS12626 datasheet.