ICS557-03 Datasheet, PDF (2/10 Pages) Integrated Circuit Systems – PCI-EXPRESS CLOCK SOURCE

ICS557-03
PCI-EXPRESS CLOCK SOURCE
PCIE SSCG
Pin Assignment
S0 ¹
S1 2
SS0 3
X1/ICLK 4
X2 5
OE 6
GNDXD ⁷
SS1 ⁸
16 VDDXD
15 CLK0
14 CLK0
13 GNDODA
12 VDDODA
11 CLK1
10 _CLK1
9
IREF
16-pin (173 mil) TSSOP
Pin Descriptions
Output Select Table 1 (MHz)
S1 S0 CLK(1:0), CLK(1:0)
0
0
25M
0
1
100M
1
0
125M
1
1
200M
Spread Selection Table 2
SS1 SS0 Spread%
0
0
No Spread
0
1
Down -0.5
1
0
Down -0.75
1
1
No Spread
Pin
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Pin
Name
S0
S1
SS0
X1/ICLK
X2
OE
GNDXD
SS1
IREF
CLK1
CLK1
VDDODA
GNDODA
CLK0
CLK0
VDDXD
Pin
Type
Pin Description
Input Select pin 0. See Table1. Internal pull-up resistor.
Input Select pin 1. See Table 1. Internal pull-up resistor.
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.
Input Output enable. Tri-states outputs and device is not shut down. Internal
pull-up resistor.
Power Connect to ground.
Input Spread Select pin 1. See Table 2. Internal pull-up resistor.
Output Precision resistor attached to this pin is connected to the internal current
reference.
Output HCSL complimentary clock output 1.
Output HCSL true clock output 1.
Power Connect to voltage supply +3.3 V for output driver and analog circuits
Power Connect to ground.
Output HCSL complimentary clock output 0.
Output HCSL true clock output 0.
Power Connect to voltage supply +3.3 V for crystal oscillator and digital circuit.
IDT™ / ICS™ PCI-EXPRESS CLOCK SOURCE
2
ICS557-03 REV K 102907