ICS557-03
PCI-EXPRESS CLOCK SOURCE
Description
Features
The ICS557-03 is a spread spectrum clock generator
supporting PCI-Express and Ethernet requirements.
The device is used for PC or embedded systems to
substantially reduce electromagnetic interference
(EMI). The device provides two differential (HCSL)
spread spectrum outputs. This device is pin configured
to select spread and clock selection. Using ICS’
patented Phase-Locked Loop (PLL) techniques, the
device takes a 25 MHz crystal input and produces two
pairs of differential outputs (HCSL) at 25 MHz, 100
MHz, 125 MHz and 200 MHz clock frequencies. It also
provides spread selection of 0.25%, -0.5%, -0.75%,
and no spread.
• Packaged in 16-pin TSSOP
• Available in Pb (lead) free package
• Supports LVDS Output Levels
• Operating voltage of 3.3 V
• Input frequency of 25 MHz
• Outputs (HCSL, 0.7 V Current mode differential pair)
• Jitter 100 ps (peak-to-peak)
• Spread of 0.25%, -0.5%, -0.75%, and no spread.
• Industrial and commercial temperature ranges
Block Diagram
VDD
2
SS1:SS0
2
CLK0
CLK0
Control
Logic
S1:S0
2
Phase Lock Loop
CLK1
CLK1
X1/ICLK
Clock
Buffer/
25 MHz
Crystal
crystal or clock
Oscillator
X2
2
GND
Optional tuning crystal
capacitors
Rr(IREF)
OE
MDS 557-03 E
1
Revision 061005
Integrated Circuit Systems ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com
ICSI [ INTEGRATED CIRCUIT SOLUTION INC ]
