ICS181-51
L
OW
EMI C
LOCK
G
ENERATOR
Pin Assignment
X1/CLKIN
X2
GND
SS%
1
2
3
4
8
7
6
5
FS2
FS1
VDD
CLKOUT
Spread Spectrum Select Table
SS%
(Pin 4)
0
1
Spread
Direction
Center
Center
Spread
Percentage (%)
+/-0.625%
+/1.875%
8 pin (150 mil) SOIC
0 = connect to GND
1 = connect directly to VDD
Note: SS% pin has an internal pull-up resistor
Frequency Range Selection Table
FS2
(Pin 8)
FS1
(Pin 7)
Frequency
Range Selection
(MHz)
28-38
38-48
46-60
58-75
0
0
1
1
0
1
0
1
Pin Descriptions
Pin
Number
Pin
Name
Pin Type
Pin Description
1
2
3
4
5
6
7
8
X1/CLKIN
X2
GND
SS%
CLKOUT
VDD
FS1
FS2
Input
Output
Power
Input
Output
Power
Input
Input
Crystal or Clock Input.
Crystal output. Float for a clock input.
Connect to ground.
Select pin for spread amount. See table above. Internal pull-up resistor.
Spread spectrum clock output per table above.
Connect to 3.3 V or 5 V.
Select pin for input frequency. See table above. Internal pull-up resistor.
Select pin for input frequency. See table above. Internal pull-up resistor.
MDS 181-51 A
2
l
Revision 110404
te l (4 08) 297 -1 201
l
w w w. i c s t . c o m
I n t e gra t e d C i r cu i t S y s t e m s
l
52 5 Race Stre et, San Jose, CA 95 126