2D Hall-effect speed and direction sensor ICs reduce system size
Allegro MicroSystems Europe has released a family of 2D Hall-effect latch ICs that feature both vertical and planar Hall elements. The APS12625 and APS12626 sensor ICs enable reduced system size and bill of materials (BoM) cost along with an increase in performance and flexibility due to 2D sensing. The ICs were developed in accordance with ISO 26262 and qualified per AEC-Q100, for automotive and other safety systems.
The APS12625 features speed and direction outputs and 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 degree 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, says Allegro Microsystems, and the ring magnet pitch can be changed without losing quadrature.
Allegro’s vertical Hall technology enables sensor ICs that are suited to magnetic motor/encoder applications and allow engineers to spend less time iterating designs to support changes in magnet pitch or system form-factor.
The monolithic devices include three Hall plates (one planar, two vertical), a multiplexer, a small-signal amplifier, chopper stabilisation, a Schmitt trigger, and two NMOS output transistors. They operate from 2.8 to 5.5V and up to 175 degree C junction temperature. Each tiny SOT23-5 device replaces a pair of conventional Hall-effect latch ICs. This allows redundant sensing for safety applications to be accomplished in virtually the same space as non-redundant implementations using legacy technology, advises Allegro Microsystems.