Data Sheet

VFJA922
Jitter Attenuator with 25MHz and
156.25 MHz Output Frequencies
Features





RoHS Status
2 LVCMOS outputs at 25 MHz
1 LVPECL output at 156.25 MHz
Ultra Low Jitter 0.25ps RMS
Free-run mode
No external components required
Applications

Synchronous Ethernet
Description
The VFJA922 is a Jitter Attenuator that provides two LVCMOS outputs at 25MHz and one LVPECL output at
156.25 MHz. With less than 0.4 dBc of jitter peaking the device allows for cascading multiple stages within the
network. A select input [Sel] allows the user to switch from the external input reference to a free-run mode. In
free-run mode the device outputs a nominal output frequency and is not locked to the input reference clock.
The VFJA922 is available in a 19.5 mm x 15.5 mm surface mount package.
Filter
Fout 1
F in
R-Divider
VCXO
PFD
Fout 2
Sel
N- Divider
Multiplier
Fout 3
Block Diagram
75 South Street, Hopkinton, MA 01748 • 800-982-5737 • 508-435-6831 • www.valpeyfisher.com • Rev_1014
1
VFJA922
Jitter Attenuator with 25MHz and
156.25 MHz Output Frequencies
Absolute Maximum Ratings
Parameter
Supply Break
Down Voltage
Storage
Temperature
Symbol
Condition
Min
Typ
Max
Unit
Vcc
-0.5
+4.6
V
Ts
-55
+95
C
Electrical Specifications
75 South Street, Hopkinton, MA 01748 • 800-982-5737 • 508-435-6831 • www.valpeyfisher.com • Rev_1014
2
Note
VFJA922
Jitter Attenuator with 25MHz and
156.25 MHz Output Frequencies
Parameter
Output
Frequency
Output
Frequency
Symbol
Fout 1
Fout 2
Input Frequency
Fin
Input Level
Fout 1 & 2
Output Level
Logic “1”
Fout 1 & 2
Output Level
Logic “0”
Fout 3
Output Level
Logic “1”
Fout 3
Output Level
Logic “0”
Condition
Min
Fout 3
Typ
Max
Unit
25.0
MHz
156.25
MHz
25.0
MHz
Vin
Slew Rate 2.5V / ns
(min)
AC coupled internally
0.4
3.3
V p-p
Voh 1,2
IOH = 8 mA
Vcc-.1
Vcc
V
Vol 1,2
IOL = 8 mA
0.0
0.3
V
Vcc-1.145
Vcc-0.845
V
Vcc-1.945
Vcc-1.645
V
Voh 3
50 Ohm to Vcc-2V or
Thevenin Equivalent
Vol 3
0.3
Jitter RMS
12KHz to 20MHz
SSB Phase
Noise
100Hz
1KHz
10KHz
100KHz
Фn
0.3
-120
-140
-150
-160
 100
APR
Free-run
Accuracy
Modulation BW
-40ºC to +85ºC
Duty Cycle
@ 50%
Rise / Fall Time
Note
Tr/Tf
Select Input
Sel
Supply Voltage
Vcc
Input Current
Operating
Temperature
Range
Icc
dBc/Hz
@ 25 MHz
ppm
10
Start up time
@ 25 MHz
@
156.25MHz
ppm
60
45
ps
Hz
50
20% to 80%
55
%
0.6
ns
2
3
s
Logic “1”( > 2.5 V) = Free Run Mode
Logic “0”( < .4 V) = External Input Reference
3.15
3.30
3.45
V
100
Ta
-40
130
mA
+85
C
75 South Street, Hopkinton, MA 01748 • 800-982-5737 • 508-435-6831 • www.valpeyfisher.com • Rev_1014
3
Table 1
VFJA922
Jitter Attenuator with 25MHz and
156.25 MHz Output Frequencies
Environmental and Mechanical
Parameter
Mechanical Shock
Thermal Shock
Specification
Per MIL-STD-202, Method 213, Condition E
Per MIL-STD-883, Method 1011, Condition A
Vibration
Per MIL-STD-883, Method 2007, Condition A
Soldering Conditions
260C for 10s max
Hermetic Seal
Leak rate less than 5x10-8 atm.cc/s of helium (crystal only)
Pin Assignments
Connection Diagram
Vcc = 3.3V
C1
.1 uF
Pin #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Vcc=3.3V
4, 13
11
C2
.1 uF
Fout 1
Fin
1
6
Sel
3
7
Fout 2
R1
180 Ω
Fout 3
10
Description
Fin
Gnd
Sel
Vcc
Gnd
Fout 1
Fout 2
Gnd
nFout 3
Fout 3
Vcc
N/C
Vcc
Gnd
9
nFout 3
2, 5, 8, 14
R2
180 Ω
Gnd
Table 1
Sel
0
1
Input Frequency
(MHz)
25.00 MHz
Free-run Mode
Output Frequency
(MHz)
25.00 & 156.25
25.00 & 156.25
75 South Street, Hopkinton, MA 01748 • 800-982-5737 • 508-435-6831 • www.valpeyfisher.com • Rev_1014
4
VFJA922
Jitter Attenuator with 25MHz and
156.25 MHz Output Frequencies
Mechanical Outline
Recommended Pad Layout
75 South Street, Hopkinton, MA 01748 • 800-982-5737 • 508-435-6831 • www.valpeyfisher.com • Rev_1014
5
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