Texas Instruments Clock Jitter Cleaner With Dual Cascaded PLLs and Integrated 2.9 GHz VCO LMK04808BEVAL/NOPB LMK04808BEVAL/NOPB データシート
製品コード
LMK04808BEVAL/NOPB
L M K 0 4 8 X X E V A L U A T I O N B O A R D O P E R A T I N G I N S T R U C T I O N S
39
VCXO Phase Noise
-170
-160
-150
-140
-130
-120
-110
-100
-90
-80
-70
-60
-50
10
100
1000
10000
100000
1000000 10000000
1E+08
Offset (Hz)
P
h
a
s
e
N
o
is
e
(
d
B
c
/H
z)
CVHD-950-122.88
Figure 15: Crystek CVHD-950-122.88 MHz VCXO Phase Noise at 122.88 MHz
Table 12: VCXO Phase Noise
at 122.88 MHz (dBc/Hz)
Offset
Phase
Noise
10 Hz
-76.6
100 Hz
-108.9
1 kHz
-137.4
10 kHz
-153.3
100 kHz
-162.0
1 MHz
-165.7
10 MHz
-168.1
40 MHz
-168.1
Table 13: VCXO RMS Jitter
to high offset of 20 MHz
at 122.88 MHz (rms fs)
Low
Offset
Jitter
10 Hz
515.4
100 Hz
60.5
1 kHz
36.2
10 kHz
35.0
100 kHz
34.5
1 MHz
32.9
10 MHz
22.7
Clock Output Measurement Technique
The same technique was used to measure phase noise for all three output types available on the
programmable OSCout and CLKout buffers. This was achieved by terminating one side of the
LVPECL, LVDS, or LVCMOS output with a 50-ohm load, and measuring the other side single-
ended using an Agilent E5052B Source Signal Analyzer.
programmable OSCout and CLKout buffers. This was achieved by terminating one side of the
LVPECL, LVDS, or LVCMOS output with a 50-ohm load, and measuring the other side single-
ended using an Agilent E5052B Source Signal Analyzer.
Buffered OSCout Phase Noise
Both OSCout0 and OSCout1 frequencies are 122.88 MHz since the OSCout Divider is bypassed.
OSCout0 is programmed to LVCMOS mode and OSCout1 is fixed as LVPECL.
OSCout0 is programmed to LVCMOS mode and OSCout1 is fixed as LVPECL.