
FEMTOCLOCK CRYSTAL-TO-3.3V,
2.5V LVPECL CLOCK GENERATOR
ICS843251I-12
IDT / ICS 3.3V, 2.5V LVPECL CLOCK GENERATOR
1
ICS843251BGI-12 REV. A NOVEMBER 19, 2012
GENERAL DESCRIPTION
The ICS843251I-12 is a 10Gb Ethernet Clock Generator. The
ICS843251I-12 uses an 18pF parallel resonant crystal over the
range of 23.2MHz - 30MHz. For Ethernet applications, a 25MHz
crystal is used. The ICS843251I-12 uses IDT’s 3rd generation
low phase noise VCO technology, and can achieve <1ps rms
phase jitter performance over the 1.875MHz - 20MHz integration
range. The ICS843251I-12 is packaged in a small 8-pin TSSOP,
making it ideal for use in systems with limited board space.
FEATURES
One Differential LVPECL output
Crystal oscillator interface, 18pF parallel resonant crystal
(23.2MHz - 30MHz)
Output frequency range: 290MHz - 750MHz
VCO range: 580MHz - 750MHz
RMS phase jitter @ 312.5MHz, using a 25MHz crystal
(1.875MHz - 20MHz): 0.36ps (typical)
3.3V or 2.5V operating supply
-40°C to 85°C ambient operating temperature
Available in lead-free (RoHS 6) package
ICS843251I-12
8-Lead TSSOP
4.4mm x 3.0mm x 0.925mm package body
G Package
Top View
VCCA
VEE
XTAL_OUT
XTAL_IN
1
2
3
4
VCC
Q
nQ
FREQ_SEL
8
7
6
5
BLOCK DIAGRAM
OSC
Phase
Detector
VCO
580MHz - 750MHz
M = ÷25 (fixed)
FREQ_SEL
N
1
÷1
0 (default) ÷2
Q
nQ
FREQ_SEL
XTAL_IN
XTAL_OUT
Pulldown
COMMON CONFIGURATION TABLE
PIN ASSIGNMENT
s
t
u
p
n
I
y
c
n
e
u
q
e
r
F
t
u
p
t
u
O
)
z
H
M
(
y
c
n
e
u
q
e
r
F
l
a
t
s
y
r
C
)
z
H
M
(
L
E
S
_
Q
E
R
FM
N
e
u
l
a
V
n
o
i
t
a
c
i
l
p
i
t
l
u
M
N
/
M
5
21
5
21
5
25
2
6
5
20
5
22
5
.
2
15
.
2
1
3