will generate both 125MHz and 25MHz clocks with mixed
LVDS and LVCMOS/LVTTL output logic. The ICS8440258-46
uses IDT’s 3
rd
generations low phase noise VCO technology
and can achieve <1ps typical rms phase jitter, easily meeting
Ethernet jitter requirements. The ICS8440258-46 is packaged
in a small, 5mm x 5mm VFQFN package.
F
EATURES
•
Four differential LVDS outputs at 125MHz
Two LVCMOS/LVTTL single-ended outputs at 125MHz
Two LVCMOS/LVTTL single-ended outputs at 25MHz
•
Selectable crystal oscillator interface or LVCMOS/LVTTL
single-ended input
•
VCO range: 490MHz - 680MHz
•
RMS phase jitter @ 125MHz, using a 25MHz crystal
(1.875MHz - 20MHz): 0.34ps (typical)
•
Full 2.5V operating supply
•
0°C to 70°C ambient operating temperature
•
Available in both standard (RoHS 5) and lead-free (RoHS6)
packages
nXTAL_SEL
XTAL_OUT
nPLL_SEL
REF_CLK
XTAL_IN
IC
S
P
IN
A
SSIGNMENT
Q0
nQ0
GND
Q1
nQ1
V
DD
1
2
3
4
5
6
7
8
V
DDA
V
DD
32 31 30 29 28 27 26 25
24
23
nc
nc
nc
GND
Q7
V
DDO
2
Q6
GND
ICS8440258-46
32-Lead VFQFN
5mm x 5mm x 0.925mm
package body
K Package
Top View
9 10 11 12 13 14 15 16
V
DDO
1
GND
GND
V
DD
Q3
Q4
nQ3
Q5
MR
22
21
20
19
18
17
B
LOCK
D
IAGRAM
MR
Pulldown
Q0
nPLL_SEL
Pulldown
Q2
nQ2
nQ0
Q1
nQ1
25MHz
XTAL_IN
Q2
OSC
XTAL_OUT
REF_CLK
Pulldown
0
Phase
Detector
1
VCO
490-680MHz
1
÷5
0
nQ2
Q3
nQ3
Q4
nXTAL_SEL
Pulldown
÷25
Q5
Q6
Q7
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.
IDT
™
/ ICS
™
LVDS/LVCMOS FREQUENCY SYNTHESIZER
1
ICS8440258AK-46 REV B JANUARY 15, 2008
ICS8440258-46
FEMTOCLOCK™ CRYSTAL/LVCMOS-TO-LVDS/ LVCMOS FREQUENCY SYNTHESIZER
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