Si550
P
R E L I M I N A R Y
D
A TA
S
H E E T
V
O L TA G E
- C
O N T R O L L E D
C
R Y S TA L
O
S C I L L A T O R
(V CX O)
10 MH
Z T O
1.4 G H
Z
Features
Available with any-rate output
frequencies from 10 MHz to
945 MHz and selected frequencies
to 1.4 GHz
3rd generation DSPLL
®
with
superior jitter performance
3x better frequency stability than
SAW based oscillators
Internal fixed crystal frequency
ensures high reliability and low
aging
Available CMOS, LVPECL,
LVDS, & CML outputs
3.3, 2.5, and 1.8 V supply options
Industry-standard 5 x 7 mm
package and pinout
Lead-free/RoHS-compliant
Si5602
Ordering Information:
See page 8.
Applications
SONET / SDH
xDSL
10 GbE LAN / WAN
Low-jitter clock generation
Optical modules
Clock and data recovery
Pin Assignments:
See page 7.
(Top View)
V
C
1
2
3
6
5
4
V
DD
Description
The Si550 VCXO utilizes Silicon Laboratories’ advanced DSPLL
®
circuitry to
provide a low-jitter clock at high frequencies. The Si550 is available with
any-rate output frequency from 10 to 945 MHz and selected frequencies to
1400 MHz. Unlike traditional VCXO’s where a different crystal is required for
each output frequency, the Si550 uses one fixed crystal to provide a wide
range of output frequencies. This IC based approach allows the crystal
resonator to provide exceptional frequency stability and reliability. In
addition, DSPLL clock synthesis provides superior supply noise rejection,
simplifying the task of generating low-jitter clocks in noisy environments
typically found in communication systems. The Si550 IC-based VCXO is
factory configurable for a wide variety of user specifications, including
frequency, supply voltage, output format, tuning slope, and temperature
stability. Specific configurations are factory programmed at time of shipment,
thereby eliminating long lead times associated with custom oscillators.
OE
GND
CLK–
CLK+
Functional Block Diagram
V
DD
CLK–
CLK+
Fixed
Frequency
XO
Any-rate
10-1400 MHz
DSPLL
®
Clock Synthesis
ADC
Vc
OE
GND
Preliminary Rev. 0.3 4/06
Copyright © 2006 by Silicon Laboratories
Si550
This information applies to a product under development. Its characteristics and specifications are subject to change without notice.
Si550
1. Electrical Specifications
Table 1. Recommended Operating Conditions
Parameter
Supply Voltage
1
Symbol
V
DD
Test Condition
3.3 V option
2.5 V option
1.8 V option
Supply Current
I
DD
Output enabled
TriState mode
Output Enable (OE)
2
V
IH
V
IL
Operating Temperature Range
T
A
Min
2.97
2.25
1.71
—
—
0.75 x V
DD
—
–40
Typ
3.3
2.5
1.8
90
60
—
—
—
Max
3.63
2.75
1.89
—
—
—
0.5
85
mA
V
Units
V
ºC
Notes:
1.
Selectable parameter specified by part number. See Section 3. "Ordering Information" on page 8 for further details.
2.
OE pin includes a 17 kΩ pullup resistor to VDD. Pulling OE to ground causes outputs to tristate.
Table 2. V
C
Control Voltage Input
Parameter
Control Voltage Tuning Slope
1,2,3
Symbol
K
V
Test Condition
10 to 90% of V
DD
Min
—
Typ
45
90
135
180
±1
±5
10.0
—
3/8 x V
DD
Max
—
Units
ppm/V
Control Voltage Linearity
4
L
VC
BSL
Incremental
–5
–10
9.3
500
+5
+10
10.7
—
—
V
DD
%
kHz
kΩ
V
V
Modulation Bandwidth
V
C
Input Impedance
Nominal Control Voltage
Control Voltage Tuning Range
BW
Z
VC
V
CNOM
V
C
@ f
O
—
0
Notes:
1.
Positive slope; selectable option by part number. See Section 3. "Ordering Information" on page 8.
2.
For best jitter and phase noise performance, always choose the smallest K
V
that meets the application’s minimum APR
requirements. See “AN266: VCXO Tuning Slope (K
V
), Stability, and Absolute Pull Range (APR)” for more information.
3.
K
V
variation is ±28% of typical values.
4.
BSL determined from deviation from best straight line fit with V
C
ranging from 10 to 90% of V
DD
. Incremental slope
determined with V
C
ranging from 10 to 90% of V
DD
.
2
Preliminary Rev. 0.3
Si550
Table 3. CLK± Output Frequency Characteristics
Parameter
Nominal Frequency
1,2,3
Symbol
f
O
Test Condition
LVDS/CML/LVPECL
CMOS
Temperature Stability
1,4
∆f/f
O
T
A
= –40 to +85 ºC
Min
10
10
–20
–50
–100
±25
Frequency drift over
15 year life.
t
OSC
Typ
—
—
—
—
—
—
—
—
Max
945
160
+20
+50
+100
±150
±10
10
Units
MHz
ppm
ppm
ppm
ms
Absolute Pull Range
1,4
Aging
Power up Time
5
APR
—
—
Notes:
1.
See Section 3. "Ordering Information" on page 8 for further details.
2.
Specified at time of order by part number. Also available in frequencies from 970 to 1134 MHz and 1213 to 1417 MHz.
3.
Nominal output frequency set by V
CNOM
= 3/8 x V
DD
.
4.
Selectable parameter specified by part number.
5.
Time from power up or tristate mode to f
O
.
Table 4. CLK± Output Levels and Symmetry
Parameter
LVPECL Output Option
1
Symbol
V
O
V
OD
V
SE
Test Condition
mid-level
swing (diff)
swing (single-ended)
mid-level
swing (diff)
Min
V
DD
– 1.42
1.1
0.5
1.125
0.32
Typ
—
Max
V
DD
– 1.25
1.9
0.93
1.275
0.50
Units
V
V
PP
V
PP
V
V
PP
—
—
1.20
0.40
LVDS Output Option
2
V
O
V
OD
CML Output Option
2
V
O
V
OD
mid-level
swing
(diff)
I
OH
= 32 mA
I
OL
= 32 mA
—
0.70
0.8 x V
DD
V
DD
– 0.75
0.95
—
—
—
1
—
1.20
V
DD
V
V
PP
V
CMOS Output Option
3
V
OH
V
OL
—
—
—
0.4
350
—
Rise/Fall time (20/80%)
t
R,
t
F
LVPECL/LVDS/CML
CMOS with CL = 15 pF
ps
ns
Preliminary Rev. 0.3
3
Si550
Table 4. CLK± Output Levels and Symmetry (Continued)
Parameter
Symmetry (duty cycle)
Symbol
SYM
Test Condition
LVPECL:
LVDS:
CMOS:
V
DD
– 1.3 V (diff)
1.25 V (diff)
V
DD
/2
Min
45
Typ
—
Max
55
Units
%
Notes:
1.
50
Ω
to V
DD
– 2.0 V.
2.
R
term
= 100
Ω
(differential).
3.
C
L
= 15 pF
Table 5. CLK± Output Phase Jitter
Parameter
Phase Jitter (RMS)
1,2,3
for F
OUT
> 500 MHz
Symbol
Test Condition
Kv = 45 ppm/V
12 kHz to 20 MHz (OC-48)
50 kHz to 80 MHz (OC-192)
Kv = 90 ppm/V
12 kHz to 20 MHz (OC-48)
50 kHz to 80 MHz (OC-192)
Kv = 135 ppm/V
12 kHz to 20 MHz (OC-48)
50 kHz to 80 MHz (OC-192)
Kv = 180 ppm/V
12 kHz to 20 MHz (OC-48)
50 kHz to 80 MHz (OC-192)
Phase Jitter (RMS)
1,2,3
for F
OUT
of 125 to 500 MHz
Min
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Typ
0.35
0.38
0.43
0.41
0.52
0.46
0.64
0.52
0.42
0.58
0.48
0.60
0.57
0.64
0.67
0.68
Max
—
—
—
—
—
—
—
—
ps
—
—
—
—
—
—
—
—
Units
ps
φ
J
φ
J
Kv = 45 ppm/V
12 kHz to 20 MHz (OC-48)
50 kHz to 80 MHz (OC-192)
Kv = 90 ppm/V
12 kHz to 20 MHz (OC-48)
50 kHz to 80 MHz (OC-192)
Kv = 135 ppm/V
12 kHz to 20 MHz (OC-48)
50 kHz to 80 MHz (OC-192)
Kv = 180 ppm/V
12 kHz to 20 MHz (OC-48)
50 kHz to 80 MHz (OC-192)
Notes:
1.
Differential Modes: LVPECL/LVDS/CML. Refer to AN255, AN256, and AN266 for further information.
2.
For best jitter and phase noise performance, always choose the smallest K
V
that meets the application’s minimum APR
requirements. See “AN266: VCXO Tuning Slope (K
V
), Stability, and Absolute Pull Range (APR)” for more information.
3.
See “AN255: Replacing 622 MHz VCSO devices with the Si550 VCXO” for comparison highlighting power supply
rejection (PSR) advantage of Si55x versus SAW-based solutions.
4
Preliminary Rev. 0.3
Si550
Table 6. CLK± Output Period Jitter
Parameter
Period Jitter*
for F
OUT
< 160 MHz
Symbol
J
PER
Test Condition
RMS
Peak-to-Peak
Min
—
—
Typ
2
14
Max
—
—
Units
ps
*Note:
Any output mode, including CMOS, LVPECL, LVDS, CML. N = 1000 cycles.
Table 7. CLK± Output Phase Noise (Typical)
Configuration
f
C
K
V
Output
Offest Frequency (f)
100 Hz
1 kHz
10 kHz
100 kHz
1 MHz
10 MHz
100 MHz
–94
–117
–128
–135
–138
–143
n/a
74.25 MHz
45 ppm/V
CMOS
L
(f)
–74
–98
–112
–122
–134
–144
–147
–77
–101
–114
–118
–128
–144
–147
300 MHz
90 ppm/V
LVPECL
622.08 MHz
45 ppm/V
LVPECL
Units
dBc/Hz
Preliminary Rev. 0.3
5
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