ZHCSHN9A February 2018 – April 2018 LMK05028
PRODUCTION DATA.
Each REF-DPLL and TCXO-DPLL supports programmable loop bandwidth from 10 mHz to 4 kHz and can achieve jitter peaking below 0.1 dB (typical). The low-pass jitter transfer characteristic of each DPLL attenuates its reference input noise with up to 60-dB/decade roll-off above the loop bandwidth.
In 3-loop mode, the REF-DPLL loop filter output modulates the TCXO-DPLL's SDM, and the TCXO-DPLL loop filter output correspondingly modulates the APLL's SDM to steer the APLL VCO into lock with the selected REF-DPLL input.
In 2-loop REF-DPLL mode, the TCXO-DPLL is not used and the REF-DPLL loop filter output controls the APLL's SDM to steer the VCO frequency into lock with the selected REF-DPLL input.
In 2-loop TCXO-DPLL mode, the REF-DPLL is not used and the TCXO-DPLL loop filter output controls the APLL's SDM to steer the VCO frequency into lock with the TCXO input.