PCI EXPRESS™ JITTER ATTENUATOR ICS874003-02
IDT
™
/ ICS
™
PCI EXPRESS™ JITTER ATTENUATOR 1 ICS874003AG-02 REV A AUGUST 29, 2006
÷5
÷4
÷2
(default)
÷5
÷4
÷2
(default)
VCO
490 - 640MHz
Phase
Detector
M = ÷5
(fixed)
3
3
GENERAL DESCRIPTION
The ICS874003-02 is a high performance Dif-
ferential-to-LVDS Jitter Attenuator designed for
use in PCI Express systems. In some PCI Express
systems, such as those found in desktop PCs, the
PCI Express clocks are generated from a low
bandwidth, high phase noise PLL frequency synthesizer. In
these systems, a jitter attenuator may be required to attenuate
high frequency random and deterministic jitter components
from the PLL synthesizer and from the system board. The
ICS874003-02 has a bandwidth of 400kHz. The 400kHz
provides an intermediate bandwidth that can easily track
triangular spread profiles, while providing good jitter
attenuation.
The ICS874003-02 uses IDT’s 3
rd
Generation FemtoClock
TM
PLL technology to achive the lowest possible phase noise.
The device is packaged in a 20 Lead TSSOP package, making
it ideal for use in space constrained applications such as PCI
Express add-in cards.
FEATURES
• Three Differential LVDS output pairs
• One Differential clock input
• CLK and nCLK supports the following input types:
LVPECL, LVDS, LVHSTL, SSTL, HCSL
• Output frequency range: 98MHz - 320MHz
• Input frequency range: 98MHz - 128MHz
• VCO range: 490MHz - 640MHz
• Cycle-to-cycle jitter: 35ps (maximum)
• Supports PCI-Express Spread-Spectrum Clocking
• The 400kHz bandwidth mode allows the system designer to
make jitter attenuation/tracking skew design trade-offs
• 3.3V operating supply
• 0°C to 70°C ambient operating temperature
• Available in both standard (RoHS 5) and lead-free (RoHS 6)
packages
HiPerClockS™
ICS
QA0
nQA0
BLOCK DIAGRAM
OEA
F_SEL2:0
CLK
nCLK
MR
OEB
QA1
nQA1
QB0
nQB0
Pulldown
Pulldown
Pullup
Pullup
Pullup
PIN ASSIGNMENT
ICS874003-02
20-Lead TSSOP
6.5mm x 4.4mm x 0.92mm
package body
G Package
Top View
QA1
V
DDO
QA0
nQA0
MR
F_SEL0
nc
V
DDA
F_SEL1
V
DD
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
nQA1
V
DDO
QB0
nQB0
F_SEL2
OEB
GND
nCLK
CLK
OEA
Pulldown
F_SEL[2:0] FUNCTION TABLE
stupnIstuptuO
2LES_F1LES_F0LES_F0AQn/0AQ,0AQn/0AQ0BQn/0BQ
000 2÷2÷
10 0 5÷2÷
010 4÷2÷
110 2÷4÷
00 1 2÷5÷
10 1 5÷4÷
011 4÷5÷
111 4÷4÷
