ICS840N202I Datasheet, PDF (20/31 Pages) Integrated Device Technology – Fourth generation FemtoClock

ICS840N202I Data Sheet
FemtoClock® NG Universal Frequency Translator
Applications Information
Recommendations for Unused Input and Output Pins
Inputs:
Crystal Inputs
For applications not requiring the use of the crystal oscillator input,
both XTAL_IN and XTAL_OUT can be left floating. Though not
required, but for additional protection, a 1k resistor can be tied from
XTAL_IN to ground.
CLKx/nCLKx Inputs
For applications not requiring the use of either differential input, both
CLKx and nCLKx can be left floating. Though not required, but for
additional protection, a 1k resistor can be tied from CLKx to ground.
It is recommended that CLKx, nCLKx be left unconnected in
frequency synthesizer mode.
LVCMOS Control Pins
All control pins have internal pull-up or put-down resistors; additional
resistance is not required but can be added for additional protection.
A 1k resistor can be used.
Outputs:
LVCMOS Outputs
The unused LVCMOS outputs can be left floating. There should be
no trace attached.
Recommended Values for Low-Bandwidth Mode Loop Filter
External loop filter components are not needed in Frequency
Synthesizer or High-Bandwidth modes. In Low-Bandwidth mode, the
loop filter structure and components shown in Figure 8 is
recommended. Please consult IDT if other values are needed.
ICS840N202CKI REVISION A NOVEMBER 1, 2013
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