Si53308
D
U A L
1 : 3 L
O W
- J
ITT ER
A
N Y
- F
O R M A T
B
U F F E R
/ L
E V E L
T
R A N S L A T O R
Features
Two independent banks of 3
differential or 6 LVCMOS outputs
Ultra-low additive jitter: 45 fs rms
Wide frequency range: dc to
725 MHz
Any-format input with pin selectable
output formats: LVPECL, low power
LVPECL, LVDS, CML, HCSL,
LVCMOS
Synchronous output enable
Output clock division: /1, /2, /4
Low output-output skew: 25 ps
Loss of signal (LOS) monitors for
loss of input clock
Independent V
DD
and V
DDO
:
1.8/2.5/3.3 V
Selectable LVCMOS drive strength to
tailor jitter and EMI performance
Small size: 32-QFN (5 mm x 5 mm)
RoHS compliant, Pb-free
Industrial temperature range:
–40 to +85 °C
Ordering Information:
See page 29.
Applications
High-speed clock distribution
Ethernet switch/router
Optical Transport Network (OTN)
SONET/SDH
PCI Express Gen 1/2/3
Storage/Servers
Telecom
Industrial
SyncE, 1588
Backplane clock distribution
Pin Assignments
Description
The Si53308 is an ultra low jitter dual 1:3 any-format buffer with pin-selectable
output clock signal format and divider selection. The Si53308 utilizes Silicon
Laboratories' advanced CMOS technology to fanout clocks from dc to 725 MHz
with guaranteed low additive jitter, low skew, and low propagation delay variability.
The Si53308 features minimal cross-talk and provides superior supply noise
rejection, simplifying low jitter clock distribution in noisy environments.
Independent core and output bank supply pins provide integrated level translation
without the need for external circuitry.
Patents pending
Functional Block Diagram
V
REF
Vref
Generator
Power
Supply
Filtering
DIVA
V
DDOA
SFOUTA[1:0]
OEA
Q0, Q1, Q2
DivA
Q0, Q1, Q2
CLK0
CLK0
LOS0
LOS1
LOS
Monitor
DIVB
V
DDOB
SFOUTB[1:0]
OEB
Q3, Q4, Q5
DivB
Q3, Q4, Q5
CLK1
CLK1
Rev. 1.0 3/16
Copyright © 2016 by Silicon Laboratories
Si53308
Si53308
T
ABLE
Section
OF
C
ONTENTS
Page
1. Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.1. Universal, Any-Format Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.2. Input Bias Resistors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.3. Universal, Any-Format Output Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.4. Synchronous Output Enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.5. Flexible Output Divider . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.6. Output Enable Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.7. Loss of Signal (LOS) Indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.8. Power Supply (V
DD
and V
DDOX
) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.9. Output Clock Termination Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.10. AC Timing Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.11. Typical Phase Noise Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.12. Input Noise Isolation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
2.13. Power Supply Noise Rejection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
3. Pin Description: 32-Pin QFN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
4. Ordering Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
5. Package Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
5.1. 5x5 mm 32-QFN Package Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
6. PCB Land Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
6.1. 5x5 mm 32-QFN Package Land Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
7. Top Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
7.1. Si53308 Top Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
7.2. Top Marking Explanation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Document Change List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Rev. 1.0
3
Si53308
1. Electrical Specifications
Table 1. Recommended Operating Conditions
Parameter
Ambient Operating
Temperature
Supply Voltage Range*
Symbol
T
A
V
DD
LVDS, CML
Test Condition
Min
–40
1.71
2.38
2.97
LVPECL, low power LVPECL,
LVCMOS
HCSL
Output Buffer Supply
Voltage*
V
DDOX
LVDS, CML, LVCMOS
2.38
2.97
2.97
1.71
2.38
2.97
LVPECL, low power LVPECL
2.38
2.97
HCSL
2.97
Typ
—
1.8
2.5
3.3
2.5
3.3
3.3
1.8
2.5
3.3
2.5
3.3
3.3
Max
85
1.89
2.63
3.63
2.63
3.63
3.63
1.89
2.63
3.63
2.63
3.63
3.63
Unit
°C
V
V
V
V
V
V
V
V
V
V
V
V
*Note:
Core supply V
DD
and output buffer supplies V
DDO
are independent. LVCMOS clock input is not supported for
V
DD
=
1.8V but is supported for LVCMOS clock output for
V
DDOX
= 1.8V. LVCMOS outputs at 1.5V and 1.2V can be
supported via a simple resistor divider network. See “2.9.1. LVCMOS Output Termination To Support 1.5 V and 1.2 V”
Table 2. Input Clock Specifications
(V
DD
=1.8 V
5%, 2.5 V
5%, or 3.3 V
10%, T
A
=–40 to 85 °C)
Parameter
Differential Input Common
Mode Voltage
Differential Input Swing
(peak-to-peak)
LVCMOS Input High Volt-
age
LVCMOS Input Low Volt-
age
Input Capacitance
Symbol
V
CM
V
IN
V
IH
V
IL
C
IN
V
DD
= 2.5 V
5%, 3.3 V
10%
V
DD
= 2.5 V
5%, 3.3 V
10%
CLK0 and CLK1 pins with
respect to GND
Test Condition
Min
0.05
0.2
V
DD
x 0.7
—
—
Typ
—
—
—
—
5
Max
—
2.2
—
V
DD
x
0.3
—
Unit
V
V
V
V
pF
4
Rev. 1.0
Si53308
Table 3. DC Common Characteristics
(V
DD
= 1.8 V
5%,
2.5 V
5%, or 3.3 V
10%,T
A
= –40 to 85 °C)
Parameter
Supply Current
Output Buffer
Supply Current
(Per Clock Output)
@100 MHz (diff)
@200 MHz (CMOS)
Symbol
I
DD
I
DDOX
Test Condition
Min
—
Typ
65
35
35
20
35
35
5
8
15
VDD/2
—
0.5 x
VDD
—
—
—
25
25
Max
100
—
—
—
—
—
—
—
—
—
—
0.55 x
VDD
0.2 x
VDD
—
0.2xVDD
—
—
Unit
mA
mA
mA
mA
mA
mA
mA
mA
mA
V
V
V
V
V
V
k
k
LVPECL (3.3 V)
Low Power LVPECL (3.3 V)*
LVDS (3.3 V)
CML (3.3 V)
HCSL, 100 MHz, 2 pF load (3.3 V)
CMOS (1.8 V, SFOUT = Open/0),
per output, C
L
= 5 pF, 200 MHz
CMOS (2.5 V, SFOUT = Open/0),
per output, C
L
= 5 pF, 200 MHz
CMOS (3.3 V, SFOUT = 0/1),
per output, C
L
= 5 pF, 200 MHz
—
—
—
—
—
—
—
—
—
0.8 x
VDD
0.45 x
VDD
—
0.8xVDD
—
—
—
Voltage Reference
Input High Voltage
Input Mid Voltage
Input Low Voltage
Output Voltage High
(LOSx)
Output Voltage Low
(LOSx)
Internal Pull-down
Resistor
Internal Pull-up
Resistor
V
REF
V
IH
V
IM
V
IL
V
OH
V
OL
R
DOWN
R
UP
V
REF
pin
–500
A
< I
REF
< 500
A
SFOUTx, DIVx
CLK_SEL, OEx
SFOUTx, DIVx
3-level input pins
SFOUTx, DIVx
CLK_SEL, OEx
I
DD
= –1 mA
I
DD
= 1 mA
CLK_SEL, DIVx, SFOUTx
OEx, DIVx, SFOUTx
*Note:
Low-power LVPECL mode supports an output termination scheme that will reduce overall system power.
Rev. 1.0
5