On page 5 of the AD9912 datasheet, under "SYSTEM CLOCK INPUT/SYSCLK PLL Bypassed/Input Resistance" the range is specified as 2.4 to 2.9 kohms differential.  But on page 21, Figure 47 the schematic for "SYSCLK BYPASSES" shows a 500 ohm resistor to RF ground at each of the SYSCLK inputs.  That would result in 1.0 kohm differential input resistance instead of the 2.4 to 2.9 kohms specified in the table on page 5.  What am I missing?  Thanks.  Steve