Revised
-
December 2013
LMK04906 Family: Low-Noise Clock Jitter with Dual Loop PLLs
SNAU126A
37
Copyright © 2013, Texas Instruments Incorporated
Clock Outputs (CLKout)
The LMK04906 Family features programmable LVDS, LVPECL, and LVCMOS buffer modes for
the CLKoutX and OSCout0 output pairs. Included below are various phase noise
measurements for each output format. For the LMK04906B, the internal VCO frequency is 2500
MHz. The divide-by-4 CLKout frequency is 625 MHz, the divide-by-16 CLKout frequency is
156.25 MHz, and the divide-by-20 CLKout frequency is 125 MHz.
LMK04906B CLKout Phase Noise
Figure 16: LMK04906B CLKout Phase Noise
Table 13: LMK04906B Phase Noise (dBc/Hz) Phase Noise and RMS Jitter (fs)
Offset
625 MHz LVPECL
1.6
156.25 MHz
LVPECL 1.6
125 MHz
LVPECL 1.6
100 Hz
-76.0
-88.0
-90.8
1 kHz
-103.2
-115.6
-117.1
10 kHz
-118.1
-130.2
-132.2
100 kHz
-121.5
-134.0
-136.0
800 kHz
-140.5
-152.5
-154.3
1 MHz
-142.7
-154.4
-156.1
10 MHz
-154.6
-161.1
-161.7
20 MHz
-154.8
-161.1
-161.8
RMS Jitter (fs)
12 kHz to 20 MHz
146.0
147.4
149.5
RMS Jitter (fs)
1 kHz to 5 MHz
166.4
160.6
159.8
-170
-160
-150
-140
-130
-120
-110
-100
-90
-80
-70
100
1000
10000
100000
1000000
10000000
Ph
as
e N
oi
se (
dB
c/
Hz
)
Frequency Offset (Hz)
LMK04906B CLKout Phase Noise
156.25 MHz LVPECL16
125 MHz LVPECL16
625 MHz LVPECL16