SNAS522K September 2011 – December 2023 LMK03806
PRODUCTION DATA
Digital lock time for the PLL will ultimately depend upon the programming of the PLL_DLD_CNT register as discussed in Digital Lock Detect. Since the PLL Fpd in this example is 20 MHz, the lock time will = PLL_DLD_CNT / 20 MHz. If PLL_DLD_CNT is set to 10,000, the lock time will be 0.5 ms. The ppm accuracy required to indicate lock will be (2e6 × 3.7 ns × fpd) / PLL_DLD_CNT, or 14.8 ppm. Refer to Digital Lock Detect for more detail on calculating lock times.