si5315 Silicon Laboratories, si5315 Datasheet - Page 41

• Manufacturer Part Number: si5315
• Description: Synchronous Ethernet/telecom Jitter Attenuating Clock Multiplier
• Manufacturer: Silicon Laboratories

6. Crystal/Reference Clock Input
The device can use an external crystal or external clock as a reference. If an external clock is used, it must be ac
coupled. With appropriate buffers, the same external reference clock can be applied to CKINn. Although the
reference clock input can be driven single ended (See Figure 18), the best performance is with a crystal or
differential clock source.
3.3 V
8 mA output current
CMOS buffer,
Figure 17. Crystal Oscillator with Feedback Resistor
For 2.5 V operation, change 130  to 82 .
Figure 18. CMOS External Reference Circuit
C
L1
40 MHz Fundamental Crystal
130 
=13 pF
XA
Preliminary Rev. 0.2
3.3 V
R
150 
150 
0.1 F
0.1 F
XB
C
L2
=13 pF
XB
XA
Si5315
Si5315
10 k
0.6 V
Si5315
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