SPRUJ55D September 2023 – July 2025 AM263P2 , AM263P2-Q1 , AM263P4 , AM263P4-Q1
Definition of terms for ADC-RDC timing interface:
System clock freq fsys= 50MHz
System clock period Tsys= 5nS
ADC sampling frequency: fADC= 1/TADC
ADC sampling period: TADC = (17 + SOC_WIDTH) × Tsys
Resolver excitation frequency (1KHz to 20KHz): fEXC = EXC_FREQ_SEL × 100
Resolver excitation period: TEXC = 1/ fEXC (for 10KHz = 0.1mS = 20K × Tsys)
Resolver oversampling ratio (number of ADC samples over one excitation period): OVR : 2 × ADC_SAMPLE_RATE
Resolver sampling period: TEXCOVR = TEXC / OVR
(if TEXC = 0.1mS, and OVR=20, TEXC = 1K × Tsys)
Resolver demodulation frequency:
= fEXC , if DOUBLESAMPLE = 0
= 2 × fEXC , if DOUBLESAMPLE = 1
Sample_select_counter: The internal resolver counter that runs from 0 to (OVR - 1). This decides ideal sample location
Positive peak of excitation signal if doublesample = 0
Both positive and negative peak if doublesample = 1
Runs from 0 to (2 × ADC_SAMPLE_RATE – 1) for every time period of TEXC.