JAJSEZ9L march 2018 – august 2023 BQ77915
PRODUCTION DATA
The device detects a fault once the applicable fault is triggered after accumulating sufficient trigger sample counts. The filtering scheme is based on a simple add/subtract. Starting with the triggered sample count cleared, the counts go up for a sample that is taken across the tested condition (for example, above the fault threshold when looking for a fault) and the counts go down for a sample that is taken before the tested condition (that is, below the fault threshold). Figure 9-6 shows an example of a signal that triggers a fault when accumulating five counts above the fault threshold. Once a fault has been triggered, the trigger sample counts reset.
With a filtered detection, when the input signal falls below the fault threshold, the sample count does not reset but only counts down, as shown in Figure 9-6. Therefore, it is normal to observe a longer delay time if a signal is right at the detection threshold. The noise can push the delay count to be counting up and down, resulting in a longer time for the delay counter to reach its final accumulated trigger target.