ICS91309
Output to Output Skew
The skew between CLKOUT and the CLKA/B outputs is not dynamically adjusted by the PLL.Since CLKOUT is one
of the inputs to the PLL, zero phase difference is maintained from REF to CLKOUT. If all outputs are equally loaded,
zero phase difference will maintained from REF to all outputs.
If applications requiring zero output-output skew, all the outputs must equally loaded.
If the CLKA/B outputs are less loaded than CLKOUT, CLKA/B outputs will lead it; and if the CLKA/B is more loaded
than CLKOUT, CLKA/B will lag the CLKOUT.
SincetheCLKOUTandtheCLKA/Boutputsareidentical, theyallstartatthesametime, butdifferentloadscausethem
to have different rise times and different times crossing the measurement thresholds.
REF input and
all outputs
loadedEqually
REF input and CLKA/B
outputsloadedequally,with
CLKOUT loaded More.
REF input and CLKA/B
outputsloadedequally,with
CLKOUT loaded Less.
Timing diagrams with different loading configurations
0093G—02/11/04
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ICSI [ INTEGRATED CIRCUIT SOLUTION INC ]
