Offset corresponds to the displacement between the magnet and Hall-effect device, when the mechanical switch is oriented at the 0° angle. Figure 2-23 illustrates how offsets are defined in the calculator tool.

The source of offset error can be attributed to PCB manufacturing and rocker assembly manufacturing. In the example documented in this note, while the PCBs were fabricated by a PCB manufacturer, the slots for the holding rocker were hand drilled. The rocker assembly was 3D printed, and the printer has a resolution of 0.0125 to 0.05 mm. Due to the level of precision when cutting the slots, there were notable instances in which the assemblies were a little off center and their bases not flush with the board. In addition to these manufacturing and assembly errors, there was also a z-offset error contributed by the tool. The tool assumes all SOT-23 packages are 1.12-mm tall and uses that value for calculating the surface to Hall-element offset. Post analysis revealed that some package heights were as low as 0.947 mm.

Large tolerances in the x-offset, y-offset, sensor z-offset, and magnet z-offset can all have a significant impact on the B-field detected at the DUT Hall element, especially when the magnet size is small. Figure 2-24 and Figure 2-25 show how much the B_OP maximum angle can change with respect to the offset from our ideal magnet position.