ZHCS927G May 2012 – January 2018 CDCM6208
PRODUCTION DATA.
The loop filter setting and external resistor selection is important to set the PLL to best possible bandwidth and to minimize jitter. A high bandwidth (≥ 100 kHz) provides best input signal tracking and is therefore desired with a clean input reference (synthesizer mode). A low bandwidth (≤ 1 kHz) is desired if the input signal quality is unknown (jitter cleaner mode). TI provides a software tool that makes it easy to select the right loop filter components. C1, R2, and C2 are external loop filter components, connected to the ELF pin. The 3 rd pole of the loop filter is device internal with R3 and C3 register selectable.