3

Integrated

Circuit

Systems, Inc.

ICS9FG107

0863C—11/22/04

Pin Description (Continued)

PIN

#

PIN NAME

PIN TYPE

DESCRIPTION

25

DIF_STOP#

IN

Active low input to stop differential output clocks.

26

*SPREAD

IN

Asynchronous, active high input, with internal 120Kohm pull-up

resistor, to enable spread spectrum functionality.

27

**SEL14M_25M#

IN

Select 14.31818 MHz or 25 Mhz input frequency. 1 = 14.31818 MHz,

0 = 25 MHz

28

*OE_3

IN

Active high input for enabling outputs.

0 = tri-state outputs, 1= enable outputs

29

DIF_3#

OUT

0.7V differential complement clock outputs

30

DIF_3

OUT

0.7V differential true clock outputs

31

VDD

PWR

Power supply, nominal 3.3V

32

DIF_2#

OUT

0.7V differential complement clock outputs

33

DIF_2

OUT

0.7V differential true clock outputs

34

**OE_2

IN

Active high input for enabling outputs.

0 = tri-state outputs, 1= enable outputs

35

GND

PWR

Ground pin.

36

VDD

PWR

Power supply, nominal 3.3V

37

**OE_1

IN

Active high input for enabling outputs.

0 = tri-state outputs, 1= enable outputs

38

DIF_1#

OUT

0.7V differential complement clock outputs

39

DIF_1

OUT

0.7V differential true clock outputs

40

VDD

PWR

Power supply, nominal 3.3V

41

DIF_0#

OUT

0.7V differential complement clock outputs

42

DIF_0

OUT

0.7V differential true clock outputs

43

*OE_0

IN

Active high input for enabling outputs.

0 = tri-state outputs, 1= enable outputs

44

**FS1

I/O

Frequency select latch input pin / 3.3V 66.66MHz clock output.

45

*DWNSPRD#

IN

3.3V input that selects spread mode. This input is not latched at

power up.

0 = Down Spread, 1 = Center Spread

46

IREF

OUT

This pin establishes the reference current for the differential current-

mode output pairs. This pin requires a fixed precision resistor tied to

ground in order to establish the appropriate current. 475 ohms is the

standard value.

47

GNDA

PWR

Ground pin for the PLL core.

48

VDDA

PWR

3.3V power for the PLL core.

Pins preceeded by * have 120 Kohm pull DOWN resistors

Pins preceeded by ** have 120 Kohm pull UP resistors