SI5348 Datasheet, PDF (43/54 Pages) Silicon Laboratories – Network Synchronizer for SyncE/ 1588 PTP Telecom Boundary (T-BC) and Slave (T-SC) Clocks

Pin Name¹
Inputs
XA
XB
X1
X2
IN0
IN0b
IN1
IN1b
IN2
IN2b
IN3
IN4
REF
REFb
Pin Number
8
9
7
10
63
64
1
2
14
15
4
5
61
62
Outputs
OUT0
31
OUT0b
30
OUT1
35
OUT1b
34
OUT2
38
OUT2b
37
OUT3
45
OUT3b
44
OUT4
51
OUT4b
50
OUT5
54
OUT5b
53
OUT6
59
OUT6b
58
Serial Interface
I2C_SEL
39
Table 9.1. Si5348 Pin Descriptions ¹
Pin Type ^{2 Function}
Si5348 Rev D Data Sheet
Pin Descriptions
I
Crystal Input. Input pin for external crystal (XTAL).
I
I
XTAL Shield. Connect these pins directly to the XTAL ground pins. The
XTAL ground pins should be separated from the PCB ground plane. Re-
I
fer to the Si5348 Reference Manual for layout guidelines.
I
Clock Inputs. IN0-IN2 accept an input clock for synchronizing the device.
They support both differential and single-ended clock signals. Refer to In-
I
put Configuration and Terminations input termination options. These pins
I
are high-impedance and must be terminated externally. The negative side
of the differential input must be grounded through a capacitor when ac-
I
cepting a single-ended clock. IN3 and IN4 only support single ended
LVCMOS signals.These pins are high-impedance and must be termina-
I
ted externally. Unused inputs can be disabled by register configuration
I
and the pins left unconnected.
I
I
I
Reference Input. This input accepts a reference clock from a stable
source (eg. TCXO or OCXO) that is used to determine free-run frequency
I
accuracy and stability during free-run or holdover of the DSPLL or DCO.
These inputs can accept differential or single-ended connections. Refer to
the Si5348 Reference Manual for recommended TCXOs and OCXOs.
O
Output Clocks. These output clocks support a programmable signal am-
plitude and common mode voltage. Desired output signal format is config-
O
urable using register control.Termination recommendations are provided
O
in Differential Output Terminations. Unused outputs should be left uncon-
nected.
O
O
O
O
O
O
O
O
O
O
O
I
I2C Select³. This pin selects the serial interface mode as I²C (I2C_SEL =
1) or SPI (I2C_SEL = 0). This pin is internally pulled up to the voltage se-
lected by the IO_VDD_SEL register bit. This pin is 3.3 V tolerant.
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