ICS814S208I Datasheet, PDF (1/23 Pages) Integrated Device Technology – FemtoClock® Crystal-to-LVDS 8-Output Clock Synthesizer

FemtoClock^® Crystal-to-LVDS 8-Output
Clock Synthesizer
ICS814S208I
DATA SHEET
General Description
The ICS814S208I is an eight LVDS output clock synthesizer
designed for wireless infrastructure applications. The device
generates eight copies of a selectable 122.88MHz or 153.6MHz
clock signal with excellent phase jitter performance. The PLL is
optimized for a reference frequency of 30.72MHz. Both a crystal
interface and a differential system clock input are supported for the
reference frequency. An extra LVDS output duplicates the reference
frequency and is provided for clock tree cascading. The device uses
IDT’s third generation FemtoClock® technology for an optimum of
high clock frequency and low phase noise performance, combined
with a low power consumption. A PLL lock status output is provided
for monitoring and diagnosis purpose. The device supports a 3.3V
voltage supply and is packaged in a small, lead-free (RoHS 6)
48-lead VFQFN package. The extended temperature range supports
wireless infrastructure, telecommunication and networking end
equipment requirements.
Block Diagram
Features
• Third generation FemtoClock® technology
• Selectable 122.88MHz or 153.6MHz output clock synthesized
from a 30.72MHz fundamental mode crystal
• Eight differential LVDS clock outputs
• Differential reference clock input pair
• PLL lock indicator output
• Crystal interface designed for a 30.72MHz,
parallel resonant crystal
• RMS phase jitter @ 122.88MHz, using a 30.72MHz crystal
(12kHz - 20MHz): 0.650ps (typical)
• RMS phase jitter @ 153.6MHz, using a 30.72MHz crystal
(12kHz - 20MHz): 0.642ps (typical)
• LVCMOS interface levels for the control input
• Full 3.3V supply voltage
• Available in Lead-free (RoHS 6) 48-lead VFQFN package
• -40°C to 85°C ambient operating temperature
nOE_A
XTAL_IN
XTAL_OUT
REF_CLK
nREF_CLK
REF_SEL
BW[1:0]
BYPASS
N_SEL
nOE_B0
nOE_B1
nOE_B2
Pulldown
OSC
Pulldown
Pullup/
Pulldown
f_REF
0
PFD
&
1
LPF
Pulldown
Pulldown (2)
2
Pulldown
Pulldown
Pulldown
Pulldown
Pulldown
FemtoClock®
VCO
570MHz - 640MHz
÷20
1
÷20 0
N
÷5,
÷4
QLOCK
QA
nQA
QB0
nQB0
QB1
nQB1
QB2
nQB2
QB3
nQB3
QB4
nQB4
QB5
nQB5
QB6
nQB6
QB7
nQB7
ICS814S208BKILF REVISION B OCTOBER 13, 2011
1
©2011 Integrated Device Technology, Inc.