The ICS844N234I is a 4-output clock synthesizer designed for SRIO
1.3 and 2.0 reference clock applications. The device generates four
copies of a selectable 100MHz, 312.5MHz, 156.25MHz or 125MHz
clock signals with excellent phase jitter performance. The four
outputs are organized in two banks of two LVDS ouputs.The device
uses IDT’s fourth generation FemtoClock® NG technology for an
optimum of high clock frequency and low phase noise performance,
combined with low power consumption and high power supply noise
rejection. The synthesized clock frequency and the phase-noise
performance are optimized for driving SRIO 1.3 and 2.0 SerDes
reference clocks. The device supports 3.3V and 2.5V voltage
supplies and is packaged in a small, lead-free (RoHS 6) 32-lead
VFQFN package. The extended temperature range supports
wireless infrastructure, telecommunication and networking end
equipment requirements.
Features
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4
TH
generation FemtoClock® NG technology
Selectable 100MHz, 312.5MHz, 156.25MHz or 125MHz output
clock synthesized from a 31.25MHz fundamental mode crystal
Four differential LVDS clock outputs
Selectable 31.25MHz crystal interface or external reference clock
RMS phase jitter @ 156.25MHz, using a 31.25MHz crystal
(1MHz - 20MHz): 0.15ps (typical)
RMS phase jitter @ 156.25MHz, using a 31.25MHz crystal
(12kHz - 20MHz): 0.26ps (typical)
LVCMOS interface levels for the frequency select input
Full 3.3V or 2.5V supply voltage
Lead-free (RoHS 6) 32-lead VFQFN package
-40°C to 85°C ambient operating temperature
Block Diagram
XTAL_IN
OSC
XTAL_OUT
REF_CLK
REF_SEL
nBYPASS
FSELA[1:0]
FSELB[1:0]
OEA
OEB
MR
Pulldown
1
0
0
÷NA
PFD
&
LPF
FemtoClock® NG
VCO
1960-2550MHz
÷80
1
QA0
nQA0
QA1
nQA1
QB0
nQB0
QB1
nQB1
Pin Assignment
÷NB
Pulldown
Pullup
Pulldown
2
2
Pullup, Pulldown
Pullup
Pullup
Pulldown
XTAL_IN
XTAL_OUT
REF_SEL
REF_CLK
MR
nBYPASS
VDDOA
QA0
nQA0
QA1
nQA1
GND
QB0
nQB0
1
2
3
4
5
6
7
8
32 31 30 29 28 27 26 25
24
23
22
21
20
19
18
17
9 10 11 12 13 14 15 16
QB1
nQB1
VDDOB
VDDA
VDD
FSELB1
FSELB0
FSELA1
FSELA0
OEB
OEA
VDD
Pin Assignment
ICS844N234I
32-lead VFQFN
5.0mm x 5.0mm x 0.925mm, package body
K Package
Top View
GND
The Preliminary Information presented herein represents a product in pre-production. The noted characteristics are based on initial product characterization and/or qualification.
Integrated Device Technology, Incorporated (IDT) reserves the right to change any circuitry or specifications without notice..
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