SCAS931G May 2012 – January 2018 CDCM6208
PRODUCTION DATA.
Each integer output divider is made up of a continuous 10-b counter. The output buffer itself contributes only little to the total device output jitter due to a low output buffer phase noise floor. The typical output phase noise floor at an output frequency of 122.88 MHz, 20-MHz offset from the carrier measures as follows: LVCMOS: –157.8 dBc/Hz, LVDS: –158 dBc/Hz, LVPECL: –158.25 dBc/Hz, HCSL: –160 dBc/Hz. Therefore, the overall contribution of the output buffer to the total jitter is approximately 50 fs-rms (12 k – 20 MHz). An actual measurement of phase noise floor with different output frequencies for one nominal yielded the results in Table 42:
fOUT | LVDS (Y0) | PECL (Y0) | CML (Y0) | HCSL (Y4) | CMOS 3p3V (Y7) |
---|---|---|---|---|---|
737.28 MHz | –154.0 dBc/Hz | –154.8 dBc/Hz | –154.4 dBc/Hz | –153.1 dBc/Hz | –150.9 dBc/Hz |
368.64 MHz | –157.0 dBc/Hz | –155.8 dBc/Hz | –156.4 dBc/Hz | –153.9 dBc/Hz | –153.1 dBc/Hz |
184.32 MHz | –157.3 dBc/Hz | –158.6 dBc/Hz | 158.1 dBc/Hz | –154.7 dBc/Hz | –156.2 dBc/Hz |
92.16 MHz | –161.2 dBc/Hz | –161.6 dBc/Hz | –161.4 dBc/Hz | –155.2 dBc/Hz | –159.4 dBc/Hz |
46.08 MHz | –162.2 dBc/Hz | –165.0 dBc/Hz | –163.0 dBc/Hz | –154.0 dBc/Hz | –162.8 dBc/Hz |