XRK4993 Datasheet, PDF (10/13 Pages) Exar Corporation – 3.3V PROGRAMMABLE SKEW CLOCK BUFFER

XRK4993
3.3V PROGRAMMABLE SKEW CLOCK BUFFER
REV. 1.0.0
11. t_SKEWPR is defined as the skew between a pair of outputs (Qx0 and Qx1) when all eight outputs are selected for
0t_U.
12. t_SKEW0 is defined as the skew between outputs when they are selected for 0t_U. Other outputs are divided, but not
shifted.
13. There are two classes of outputs: Nominal (multiple of t_U delay) and Divided (QC[1:0] or Divide-by-4 mode).
14. t_DEV is the output-to-output skew between any two devices operating under the same conditions (V_CC ambient
temperature, air flow, etc.)
15. t_ODCV is the deviation of the output from a 50% duty cycle. Output pulse width variations are included in t_SKEW2
and t_SKEW4 specifications.
16. Specified with outputs loaded with 20pF for the XRK4993 devices. Devices are terminated through 75Ω to V_CC/2.
t_PWH is measured at 2.0V. t_PWL is measured at 0.8V.
17. t_ORISE and t_OFALL measured between 0.8V and 2.0V.
18. t_LOCK is the time that is required before synchronization is achieved. This specification is valid only after V_CC is
stable and within normal operating limits. This parameter is measured from the application of a new signal or
frequency at CLKIN or FB_IN until t_PD is within specified limits
FIGURE 6. AC TIMING DIAGRAM (SHOWN WITH PE=HIGH)
CLKIN
FB_IN
t_REF
t_{RPW H}
t_PD
t_{RPW L}
t_ODCV
t_ODCV
Any Q
OTHER Q
CLKIN DIVIDED BY 2
CLKIN DIVIDED BY 4
t_SKEWPR,
t_{SKEW0, 1}
t_{SKEW3, 4}
t_{SKEW1, 3, 4}
t_{SKEW PR,}
t_{SKEW0, 1}
t_{SKEW3, 4}
t_JR
t_{SKEW3, 4}
t_{SKEW2, 4}
10