IDTTM/ICSTM Programmable FTG for Differential P4

TM CPU, PCI-Express & SATA Clocks

ICS9FG107

REV F 08/21/07

ICS9FG107

Programmable FTG for Differential P4

TM CPU, PCI-Express & SATA Clocks

4

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 output 3.

0 = tri-state outputs, 1= enable outputs

29

DIF_3#

OUT

0.7V differential complement clock output

30

DIF_3

OUT

0.7V differential true clock output

31

VDD

PWR

Power supply, nominal 3.3V

32

DIF_2#

OUT

0.7V differential complement clock output

33

DIF_2

OUT

0.7V differential true clock output

34

OE_2**

IN

Active high input for enabling output 2.

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 output 1.

0 = tri-state outputs, 1= enable outputs

38

DIF_1#

OUT

0.7V differential complement clock output

39

DIF_1

OUT

0.7V differential true clock output

40

VDD

PWR

Power supply, nominal 3.3V

41

DIF_0#

OUT

0.7V differential complement clock output

42

DIF_0

OUT

0.7V differential true clock output

43

OE_0*

IN

Active high input for enabling output 0.

0 = tri-state outputs, 1= enable outputs

44

FS1**

IN

3.3V Frequency select latched input pin.

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 UP resistors

Pins preceeded by ** have 120 Kohm pull DOWN resistors