Figure 6-1 shows a typical phase noise performance for 156.25MHz reference
clock input from the SMA100B.
LMKDB1204EVM was configured in cascade mode to
get these measurements, which were obtained by following these steps:
- SMA100B → LMKDB1204EVM input.
Then, LMKDB1204EVM to secondary LMKDB1204 EVM. This was done to get a fast
slew rate at the input. Other methods like clipping a circuit can be used to
get a desired slew rate and square wave form as well outputted from the
SMA100B.
- Output phase noise is
measured through a Balun to the differential waveform from the LMKDB1204
into a single-ended waveform for the phase noise analyzer.