SNAS835A September 2022 – February 2025 LMK5B33414
PRODUCTION DATA
Each APLL has a 5-bit XO reference (R) divider that can be used to meet the maximum APLL PFD frequency specification. The divider can also be used to verify the APLL fractional-N divide ratio (NUM/DEN) is between 0.125 to 0.875 (avoid 0.5), which is recommended to support the DPLL frequency tuning range. Otherwise, the R divider can be bypassed (divide by 1).
For example, if the XO frequency is 48MHz, the VCBO frequency is 2500MHz, and the XO doubler is bypassed, the R divider can be set to 2 to achieve a fractional-N divide ratio of 0.16667. Otherwise, the ratio is 0.0833333 if the R divider is 1 and the XO doubler is bypassed, which limits the DPLL frequency range.