ICS91305I

HIGH PERFORMANCE COMMUNICATION BUFFER

IDT® HIGH PERFORMANCE COMMUNICATION BUFFER

5

ICS91305I

REV G 090612

Output to Output Skew

The skew between CLKOUT and the CLK(1-4) 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 CLK(1-4) outputs are less loaded than CLKOUT, CLK(1-4) outputs will lead it; and if the CLK(1-4) is more loaded than

CLKOUT, CLK(1-4) will lag the CLKOUT.

Since the CLKOUT and the CLK(1-4) outputs are identical, they all start at the same time, but different loads cause them to

have different rise times and different times crossing the measurement thresholds.

Timing diagrams with different loading configurations