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Crystal Start-Up and PCB Layout

Question asked by BrettG on Sep 27, 2011
Latest reply on Sep 27, 2011 by BrettG

In the system shown below, there were intermittent failures on the crystal startup for several units. The device in the middle is the ADAU1701. C71 and C77 are the load capacitors and R88 is the damping resistor. The dark green is the ground plane layer and the light blue is the top side traces to the ADAU1701.

 

The load capacitance and damping resistance values were changed to various values within +/- 25% of the suggested values, but there was no set of values that yielded consistent start-up.

 

ScreenHunter_01 Sep. 27 13.46.jpg

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