Configuration With External Crystal Oscillator - Analog Devices Hittite HMC764LP6CE Operating Manual

v01.0910
PLLs WITH INTEGRATED VCO - MICROWAVE APPLICATIONS
EVALUATION BOARD OPERATING GUIDE
4.2

Configuration with External Crystal Oscillator

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if it is desired to use the evaluation board with an external crystal oscillator, disable the VcXo regulator
u6 by shorting JP4, and connect the external source to J2 as shown in Figure 3. if the external source
has sufficient drive (see the reference sensitivity plots in datasheets) it is likely not necessary to remove
c34, at the output of the on-board crystal oscillator, otherwise remove c34 from the board. the evaluation
board has been tested with an external 100 MHz sine crystal with c34 in place with no measurable effects,
however an external square wave oscillator may be more sensitive to mismatch caused by c34, hence if
in doubt, remove c34.
Figure 3. Typical Setup of the PLL with Integrated VCO Evaluation Board with External Crystal Oscillator
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