
DATASHEET
PCI-EXPRESS GEN1 CLOCK SOURCE
ICS557-01
IDT PCI-EXPRESS GEN1 CLOCK SOURCE
1
ICS557-01
REV P 072512
Description
The ICS557-01 is a clock chip designed for use in
PCI-Express Cards as a clock source. It provides a pair of
differential outputs at 100 MHz in a small 8-pin SOIC
package.
Using IDT’s patented Phase-Locked Loop (PLL)
techniques, the device takes a 25 MHz crystal input and
produces HCSL (Host Clock Signal Level) differential
outputs at 100 MHz clock frequency. LVDS signal levels can
also be supported via an alternative termination scheme.
Features
Supports PCI-ExpressTM HCSL Outputs
0.7 V current mode differential pair
Supports LVDS Output Levels
Packaged in 8-pin SOIC
RoHS 5 (green) or RoHS 6 (green and lead free)
compliant packaging
Operating voltage of 3.3 V
Low power consumption
Input frequency of 25 MHz
Short term jitter 100 ps (peak-to-peak)
Output Enable via pin selection
Industrial temperature range available
For PCIe Gen2 applications, see the 5V41064
For PCIe Gen3 applications, see the 5V41234
Block Diagram
Phase Lock
Loop
Clock
Buffer/
Crystal
Oscillator
VDD
GND
X2
25 MHz
crystal /clock
CLK
OE
CLK
R
R(IREF)
X1
Crystal Tuning Capacitors