SPRZ455D december 2020 – june 2023 DRA829J , DRA829J-Q1 , DRA829V , DRA829V-Q1 , TDA4VM , TDA4VM-Q1
ADVANCE INFORMATION
POK: De-Glitch (filter) is based upon only two samples
The POK is sampled on an approximate period of 1.25us. The "near-by" sample history is saved in a circular buffer. The De-Glitch (filter) is designed to AND the last n entries from the sample history in order to generate the output (to the ESM).
The De-Glitch filter checks only the last entry (0th) and four samples ago (3rd). The filter ANDs these two results (instead of 4) in order to to generate the FAIL output to the ESM.
Notice that when the POK is set to monitor a fixed threshold (UV or OV but not set to ping-pong), the un-checked samples will be used.
Using J7ES as an example: On the next sample of the POK, the previously ignored 2nd sample will be incremented to the 3rd place and will therefore be included in the generation of the FAIL output.
When the POKs are controlled in a ping-pong manner, the skipped samples will be discarded.
There is no workaround.
However, the intent of the De-Glitch (filtering) is to insure that a discrete voltage dip or rise does not trigger FAIL. The sampling of two points significantly separated in time means that the voltage dip / rise was not a single isolated event.
Since the filter requires all N samples to fail before generating a FAIL signal to the ESM, the inclusion of 2 points instead of N makes this circuit more sensitive.