Si5320
SONET/SDH P
R E C I S I O N
C
L O C K
M
U L T I P L I E R
I C
Features
Ultra-low-jitter clock output with
jitter generation as low as
0.3 ps
RMS
No external components
(other than a resistor and
standard bypassing)
Input clock ranges at 19, 39, 78,
155, 311, and 622 MHz
Output clock ranges at 19, 155,
or 622 MHz
Digital hold for loss of input clock
Support for forward and reverse
FEC clock scaling
Selectable loop bandwidth
Loss-of-signal alarm output
Low power
Small size (9x9 mm)
Si5320
Si5320
Applications
SONET/SDH line/port cards
Optical modules
Core switches
Digital cross connects
Terabit routers
Ordering Information:
See page 29.
Description
The Si5320 is a precision clock multiplier designed to exceed the requirements of
high-speed communication systems, including OC-192/OC-48 and 10 GbE. This
device phase locks to an input clock in the 19, 39, 78, 155, 311, or 622 MHz
frequency range and generates a frequency-multiplied clock output that can be
configured for operation in the 19, 155, or 622 MHz range. Silicon Laboratories’
DSPLL
™
technology delivers all PLL functionality with unparalleled performance
while eliminating external loop filter components, providing programmable loop
parameters, and simplifying design. FEC rates are supported with selectable 255/
238 or 238/255 scaling of the clock multiplication ratios. The Si5320 establishes a
new standard in performance and integration for ultra-low-jitter clock generation. It
operates from a single 3.3 V supply.
Functional Block Diagram
REXT
VSEL33
V DD
GND
Biasing & Supply Regulation
FXDDELAY
CLKIN+
CLKIN–
2
CAL_ACTV
÷
Signal
Detect
3
M
DSPLL
T
DH_ACTV
÷
Calibration
VALTIME
LOS
2
CLKOUT+
CLKOUT–
FRQSEL[1:0]
RSTN/CAL
2
2
INFRQSEL[2:0]
FEC[1:0]
DBLBW
BWSEL[1:0]
Rev. 2.3 4/05
Copyright © 2005 by Silicon Laboratories
Si5320
Si5320
N
OTES
:
2
Rev. 2.3
Si5320
T
A B L E O F
C
O N T E N TS
Section
Page
1. Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
2. Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.1. DSPLL™ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
2.2. Clock Input and Output Rate Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
2.3. PLL Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.4. Digital Hold of the PLL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.5. Hitless Recovery from Digital Hold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
2.6. Loss-of-Signal Alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
2.7. Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.8. PLL Self-Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.9. Bias Generation Circuitry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
2.10. Differential Input Circuitry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.11. Differential Output Circuitry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.12. Power Supply Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.13. Design and Layout Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3. Pin Descriptions: Si5320 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
4. Ordering Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
5. Package Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
6. 9x9 mm CBGA Card Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Document Change List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Contact Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
Rev. 2.3
3
Si5320
1. Electrical Specifications
Table 1. Recommended Operating Conditions
Parameter
Ambient Temperature
Si5320 Supply Voltage
3
When Using 3.3 V Supply
Symbol
T
A
V
DD33
Test Condition
Min
1
–20
2
3.135
Typ
25
3.3
Max
1
85
3.465
Unit
°C
V
Notes:
1.
All minimum and maximum specifications are guaranteed and apply across the recommended operating conditions.
Typical values apply at nominal supply voltages and an operating temperature of 25 °C unless otherwise stated.
2.
The Si5320 is guaranteed by design to operate at –40° C. All electrical specifications are guaranteed for an ambient
temperature of –20 to 85° C.
3.
The Si5320 specifications are guaranteed when using the recommended application circuit (including component
tolerance) of Figure 5 on page 15. 3.3 V operation uses an on-chip voltage regulator and is recommended.
4
Rev. 2.3
Si5320
C LKIN +
C LKIN –
V
IS
A. O peration with Single-Ended C lock Input
N ote: W hen using single-ended clock sources, the unused clock
input on the Si5320 m ust be ac-coupled to ground.
C LKIN +
C LKIN –
0.5 V
ID
(C LKIN+) – (C LKIN –)
V
ID
B. O peration with D ifferential C lock Input
N ote: Transm ission line term ination, when required, m ust be provided
externally.
Figure 1. CLKIN Voltage Characteristics
80%
20%
t
F
t
R
Figure 2. Rise/Fall Time Measurement
(C L K IN + ) – (C L K IN – )
0 V
t
LOS
Figure 3. Transitionless Period on CLKIN for Detecting a LOS Condition
Rev. 2.3
5