PRELIMINARY
VCXO JITTER ATTENUATOR &
FEMTOCLOCK™ MULTIPLIER
ICS814252I-02
GENERAL DESCRIPTION
FEATURES
The ICS814252I-02 is
a
member of the
• Two LVDS outputs
ICS
HiperClockS™ family of high performance clock
solutions from IDT. The ICS814252I-02 is a PLL
based synchronous multiplier that is optimized for
PDH or SONET to Ethernet clock jitter attenuation
Each output supports independent frequency selection at
25MHz, 125MHz, 156.25MHz and 312.5MHz
HiPerClockS™
• Two differential inputs support the following input types:
LVPECL, LVDS, LVHSTL, SSTL, HCSL
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™ 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.
• 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 frequency multiplier provides low jitter, high
frequency output
• Absolute pull range: 50ppm
• FemtoClock VCO frequency: 625MHz
• RMS phase jitter @ 125MHz, using a 25MHz crystal
(10kHz – 20MHz): 1.2ps (typical)
• 3.3V supply voltage
• -40°C to 85°C ambient operating temperature
• Available in both standard (RoHS 5) and lead-free (RoHS 6)
packages
PIN ASSIGNMENT
32 31 30 29 28 27 26 25
LF1
LF0
1
2
3
4
5
6
7
8
24
23
22
21
20
19
18
17
GND
nQB
ISET
QB
GND
VDDO
nQA
ICS814252I-02
CLK_SEL
VDD
QA
RESERVED
GND
GND
ODASEL_0
9 10 11 12 13 14 15 16
32-Lead VFQFN
5mm x 5mm x 0.925 package body
K Package
Top View
The Preliminary Information presented herein represents a product in pre-production.The noted characteristics are based on initial product characterization
and/or qualification.Integrated DeviceTechnology, Incorporated (IDT) reserves the right to change any circuitry or specifications without notice.
IDT™ / ICS™ VCXO JITTER ATTENUATOR/MULTIPLIER
1
ICS814252CKI-02 REV. A OCTOBER 5, 2007