JAJSTE0 March 2024 LMK05318B-Q1
PRODUCTION DATA
APLL1 supports a programmable loop bandwidth from 100Hz to 10kHz (typical range), and APLL2 supports a programmable loop bandwidth from 100kHz to 1MHz (typical range). The loop filter components can be programmed to optimize the APLL bandwidth depending on the reference input frequency and phase noise. The LF1 (pin 29) and LF2 (pin 34), each require an external APLLn second order "C2" capacitor to ground. See the suggested values for the LF1 and LF2 capacitors in Pin Configuration and Functions.
Figure 7-23 shows the APLL loop filter structure between the PFD/charge pump output and VCO control input. For APLL1, the loop filter capacitors are fixed for "C1", "C3", and "C4" to 100pF, 70pF, and 70pF, respectively. For APLL2, only "C1" is fixed to 100pF, the rest of the components are programmable.
PLLATINUMSIM-SW can be used for APLL Loop Filter simulation.