A phase locked loop circuit, system, and method of operation are provided.
The phase-locked loop (PLL) includes a first PLL and a second PLL. The
first PLL is nested inside the second PLL. According to one embodiment,
the first PLL is coupled to the output of a surface acoustic wave (SAW)
resonator, and includes first divider coupled within a feedback loop of
the first PLL. The second PLL is coupled between an input of the overall
PLL circuit, and output from the first PLL and the first divider.
According to a second embodiment, the second PLL includes a SAW
voltage-controlled oscillator (VCSO) and a second divider coupled to an
output of the first PLL. Regardless of whether the first or second
embodiments are contemplated, the nested first and second PLL circuits
provide an agile, low phase noise, clock synthesizer and jitter
attenuator hereof.