Each APLL has a post divider which provides a VCO
post divider frequency calculated in Equation 6,
Equation 7,
or Equation 8.
The final output frequency is calculated by dividing from the VCO
post divider frequency and the output divide (see Equation 9).
For each output, the output frequency depends on the selected APLL
clock source and output divider value.
Equation 6. APLL1 selected: fPOST_DIV =
fVCO1 / PnAPLL1
Equation 7. APLL2 selected: fPOST_DIV =
fVCO2 / P1APLL2
Equation 8. BAW APLL selected: fPOST_DIV
= fVCBO / P1APLL3
Equation 9. OUTx: fOUTx =
fPOST_DIV / ODOUTx
where
- fPOST_DIV: Output mux source frequency
(APLL1, APLL2 or BAW APLL post-divider clock)
- PnAPLL1: APLL1 primary P1 or secondary
P2 post-divide value (2 to 7)
- P1APLL2: APLL2 primary P1 post-divide
value (2 to 13)
- P1APLL3: APLL3 (BAW) post-divide value
= div8 (2 to 8) , div8 times 2 (10, 12, 14, 16) , or bypass
(1)
- fOUTx: Output clock frequency (x = 0 to 15)
- ODOUTx: OUTx output bypass or divider value. All outputs have a
12-bit divider with values 1 to (212 – 1). All
outputs (except OUT2 and OUT3) have the option
to follow the 12-bit divider with a 20-bit SYSREF divider
that can be used to produce 1PPS or other frequencies below
1Hz when the SYSREF output is set for continuous
output.