SI5341-EVB Datasheet, PDF (5/18 Pages) Silicon Laboratories – Powered from USB port or external power supply

Si5341-EVB
6. Clock Input Circuits (INx/INxB and FB_IN/FB_INB)
The Si5341-EVB has eight SMA connectors (IN0/IN0B–IN2/IN3B and FB_IN/FB_INB) for receiving external clock
signals. All input clocks are terminated as shown in Figure 4 below. Note input clocks are AC coupled and 50 ohm
terminated. This represents 4 differential input clock pairs. Single-ended clocks can be used by appropriately
driving one side of the differential pair with a single-ended clock. For details on how to configure inputs as
single-ended, please refer to the Si5341 data sheet.
Figure 4. Input Clock Termination Circuit
7. Clock Output Circuits (OUTx/OUTxB)
Each of the twenty output drivers (10 differential pairs) is AC coupled to its respective SMA connector. The output
clock termination circuit is shown in Figure 5 below. The output signal will have no dc bias. If DC coupling is
required, the AC coupling capacitors can be replaced with a resistor of appropriate value. The Si5341-EVB
provides pads for optional output termination resistors and/or low frequency capacitors. Note that components with
schematic “NI” designation are not normally populated on the Si5341-EVB and provide locations on the PCB for
optional DC/AC terminations by the end user.
Figure 5. Output Clock Termination Circuit
Rev. 1.1
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