Silicon Laboratories SI5369 Clock User Manual


 
Si53xx-RM
28 Rev. 0.5
3.12. Si5368
The Si5368 is a jitter-attenuating precision clock multiplier for applications requiring sub 1 ps rms jitter
performance. The Si5368 accepts four clock inputs ranging from 2 kHz to 710 MHz and generates five
independent, synchronous clock outputs ranging from 2 kHz to 945 MHz and select frequencies to 1.4 GHz. The
device provides virtually any frequency translation combination across this operating range. The Si5368 input clock
frequency and clock multiplication ratio are programmable through an I
2
C or SPI interface. The DSPLL loop
bandwidth is digitally programmable from 60 Hz to 8 kHz, providing jitter performance optimization at the
application level. Operating from a single 1.8, 2.5, or 3.3 V supply, the Si5368 is ideal for providing clock
multiplication and jitter attenuation in high performance timing applications. See "7. Microprocessor Controlled
Parts (Si5319, Si5324, Si5325, Si5326, Si5327, Si5367, Si5368, Si5369, Si5374, Si5375)" on page 76 for a
complete description.
Figure 12. Si5368 Clock Multiplier and Jitter Attenuator Block Diagram
C2A
CS0_C3A
C2B
CS1_C4A
INT_ALM
C1A
CKIN_1+
CKIN_1–
CKIN_2+
CKIN_2–
C3B
CKIN_3+
CKIN_3–
CKIN_4+
CKIN_4–
C1B
CKIN_3
CKIN_4
CKOUT_2
VDD
GND
CKOUT_1+
CKOUT_1–
÷ NC1
1
0
CKOUT_2+
CKOUT_2–
÷ NC2
1
0
CKOUT_3+
CKOUT_3–
÷ NC3
1
0
CKOUT_4+
CKOUT_4–
÷ NC4
1
0
2
2
2
2
2
2
2
2
f
OSC
Xtal or Refclock
RATE[1:0]
XA
XB
f
x
DSBL2/BYPASS
DSBL34
DSBL5
FSYNC
LOGIC/
ALIGN
SDA_SDO
SCL
SDI
A[1:0]
INC
DEC
FS_ALIGN
RST
CMODE
BYPASS/DSBL2
LOL
Control
÷ N3_2
÷ N3_1
FSYNC
÷ N2
÷ N3_3
÷ N3_4
CKOUT_5+
CKOUT_5–
÷ NC5
1
0
2
1
0
A[2]/SS
÷ N1_HS
DSPLL
®
f
3
3