DATA SHEET
ICS813N252AKI-04 REVISION A MAY 24, 2011 1 ©2011 Integrated Device Technology, Inc.
VCXO Jitter Attenuator &
FemtoClock
®
NG Multiplier
ICS813N252I-04
General Description
The ICS813N252I-04 is a PLL based synchronous multiplier that is
optimized for PDH or SONET to Ethernet clock jitter attenuation and
frequency translation. The device contains two internal frequency
multiplication stages that are cascaded in series. The first stage is a
VCXO PLL that is optimized to provide reference clock jitter
attenuation. The second stage is a FemtoClock
®
NG frequency
multiplier that provides the low jitter, high frequency Ethernet output
clock that easily meets Gigabit and 10 Gigabit Ethernet jitter
requirements. Pre-divider and output divider multiplication ratios are
selected using device selection control pins. The multiplication ratios
are optimized to support most common clock rates used in PDH,
SONET and Ethernet applications. The VCXO requires the use of an
external, inexpensive pullable crystal. The VCXO uses external
passive loop filter components which allows configuration of the PLL
loop bandwidth and damping characteristics. The device is
packaged in a space-saving 32-VFQFN package and supports
industrial temperature range.
Features
• Fourth generation FemtoClock® Next Generation (NG)
technology
• One LVPECL output pair and one LVDS output pair
Each output supports independent frequency selection at 25MHz,
125MHz, 156.25MHz and 312.5MHz
• Two differential inputs support the following input types: LVPECL,
LVDS, LVHSTL, SSTL, HCSL
• Accepts input frequencies from 8kHz to 155.52MHz including
8kHz, 1.544MHz, 2.048MHz, 19.44MHz, 25MHz, 77.76MHz,
125MHz and 155.52MHz
• Attenuates the phase jitter of the input clock by using a low-cost
pullable fundamental mode VCXO crystal
• VCXO PLL bandwidth can be optimized for jitter attenuation and
reference tracking using external loop filter connection
• FemtoClock NG frequency multiplier provides low jitter, high
frequency output
• Absolute pull range: 100ppm
• FemtoClock NG VCO frequency: 625MHz
• RMS phase jitter @ 125MHz, using a 25MHz crystal
(12kHz – 20MHz): 0.3ps (typical)
• 3.3V supply voltage
• -40°C to 85°C ambient operating temperature
• Available in lead-free (RoHS 6) package
9 10 11 12 13 14 15 16
32 31 30 29 28 27 26 25
1
2
3
4
5
6
7
8
24
23
22
21
20
19
18
17
LF1
LF0
ISET
V
EE
CLK_SEL
V
CC
RESERVED
V
EE
VEE
nQB
QB
V
CCO
nQA
QA
V
EE
ODASEL_0
PDSEL_2
PDSEL_1
PDSEL_0
V
CC
VCCA
ODBSEL_1
ODBSEL_0
ODASEL_1
XTAL_IN
XTAL_OU
CLK0
nCLK0
V
CC
CLK1
nCLK1
V
CCX
Pin Assignment
ICS813N252I-04
32 Lead VFQFN
5mm x 5mm x 0.925mm package body
K Package
Top View
