ICS557-03
PCI-EXPRESS CLOCK SOURCE
Output Select Table 1(MHz)
Pin Assignment
S1
0
S0
0
CLK(1:0), CLK(1:0)
1
VDDXD
CLK0
16
15
14
13
12
11
10
9
S0
25M
100M
125M
200M
0
1
S1
SS0
2
3
4
5
6
7
8
1
0
CLK0
1
1
X1/ICLK
X2
GNDODA
VDDODA
CLK1
Spread Selection Table 2
OE
SS1
SS0
0
Spread %
Center 0.25
Down -0.5
0
0
1
1
GNDXD
SS1
CLK1
IREF
1
0
Down -0.75
No Spread
1
16-pin (173 mil) TSSOP
Pin Descriptions
Pin
Number
Pin
Name
Pin
Type
Pin Description
1
2
3
4
5
6
S0
S1
Input Select pin 0. See Table1. Internal pull-up resistor.
Input Select pin 1. See Table 1. Internal pull-up resistor.
SS0
X1/ICLK
X2
Input Spread Select pin 0. See Table 2. Internal pull-up resistor.
Input Crystal or clock input. Connect to a 25 MHz crystal or single ended clock.
Output Crystal connection. Leave unconnected for clock input.
OE
Input Output enable tri-states outputs and device is not shut down. Internal
pull-up resistor.
7
8
9
GNDXD
SS1
Power Connect to ground.
Input Spread Select pin 1. See Table 2. Internal pull-up resistor.
IREF
Output Precision resistor attached to this pin is connected to the internal current
reference.
10
11
12
13
14
15
16
CLK1
CLK1
Output HCSL compliment clock output.
Output HCSL clock output.
VDDODA
GNDODA
CLK0
Power Connect to voltage supply +3.3 V for output driver and analog circuits
Power Connect to ground.
Output HCSL compliment clock output.
CLK0
Output HCSL clock output.
VDDXD
Power Connect to voltage supply +3.3 V for crystal oscillator and digital circuit.
MDS 557-03 E
2
Revision 061005
Integrated Circuit Systems ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com
ICSI [ INTEGRATED CIRCUIT SOLUTION INC ]
