SPRUJ55D September 2023 – July 2025 AM263P2 , AM263P2-Q1 , AM263P4 , AM263P4-Q1
This is the recommended mode of operation if the zero-position of the rotor is in Q1 region(described earlier in Section 7.5.3.2.2.1.4GUID-BFA7C918-7729-4D7E-BAC1-F793EBFA867B.html#IMAGE_NLK_VL2_5YB) during detection. Both Sin and Cos channels will be positive, the algorithm will select the strongest signal.
Ideal sample time selection is done in two phases.
Phase-1: In the first phase RDC checks the sine channel and cosine channels (clock: oversample coefficient × excitation frequency). It has one counter for sine, and one counter for cosine. These counters get incremented each time a sample is above SAMPLE_DET_THRESHOLD. When total number of samples of both counters reach 2PEAK_AVG_LIMIT, two counters are compared. The counter with a larger count is selected as the valid channel to detect demodulation peak. If they are equal, sin channel is selected.
Phase-2: In the second phase, a moving average of 3 samples is continuously compared to each other. If the average starts falling down while previously was moving up, or equal, this is recorded as the local peak. In order to avoid false triggers when the signal is low, samples below SAMPLE_DET_THRESHOLD are ignored. After 2PEAK_AVG_LIMIT , ideal local peaks are collected and are averaged to find the ideal peak sampling point.