JAJU835 December 2021
The magnetic flux density detected at switches U1 and U2 were simulated to determine appropriate placement of the Hall-effect sensors. For simulation, the distance measurements are done with respect to the sensing element to the magnet since the simulation tool does not automatically consider the location of the sensing element within the device.
Figure 2-16 shows a plot of the simulation results for the U1 and U2 sensors. If the sensed magnetic flux density of U1 is above the U1 OUT LOW horizontal line (BOP,MAX) in the results, the output of U1 is assured to be low. If the sensed magnetic flux density of U1 is below the U1 OUT HIGH horizontal line (BRP,MIN) in the results, the output of U1 is assured to be high. Similarly, if the sensed magnetic flux density of U2 is below the U2 OUT LOW horizontal line (BOP,MIN) in the results and it is powered, the output of U2 is assured to be low. If the sensed magnetic flux density of U2 is above the U2 OUT HIGH horizontal line (BRP,MAX) in the results and it is powered, the output of U2 is assured to be high.
In the results, notice that the output of U1 is not ensured to be low until the trigger is pressed at least 0.3 mm. The output on U2; however, is always asserted low as long as it is powered. If the output of U1 is not asserted low, U2 is not powered.