yfluo2004
Junior Member level 1
cppsim
Hi,
I am currently designing a PLL and using cppsim - PLL Design Assistant, to do the system simulation. When I simulate the PLL phase noise, I first specify the detector noise and VCO phase noise and then observe the PLL phase noise. I attached the phasenoise waveform. The setup for the detector noise is -90dBc/Hz; the VCO phase noise is -105dBc/Hz at 1MHz offset; the bandwidth is 3.88MHz with fz/fo=1/8.
Is the VCO phase noise the free running phase noise in the PLL Design Assistant setup window? Is the PLL phase noise supposed to be smaller than the VCO free running phase noise while here it seems the summation of the detector noise and phase noise? I am a little confused about that.
Could somebody give me some suggestions? Thanks a lot!
YLuo
Hi,
I am currently designing a PLL and using cppsim - PLL Design Assistant, to do the system simulation. When I simulate the PLL phase noise, I first specify the detector noise and VCO phase noise and then observe the PLL phase noise. I attached the phasenoise waveform. The setup for the detector noise is -90dBc/Hz; the VCO phase noise is -105dBc/Hz at 1MHz offset; the bandwidth is 3.88MHz with fz/fo=1/8.
Is the VCO phase noise the free running phase noise in the PLL Design Assistant setup window? Is the PLL phase noise supposed to be smaller than the VCO free running phase noise while here it seems the summation of the detector noise and phase noise? I am a little confused about that.
Could somebody give me some suggestions? Thanks a lot!
YLuo