Frequency Generator for CPU, QPI, FBD, PCIe Gen 2 & SATA

ICS9FG108

REV G 04/06/07

ICS9FG108

Frequency Generator for CPU, QPI, FBD, PCIe Gen 2 & SATA

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 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

I/O

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

45

**FS0

IN

3.3V Frequency select latched input pin.

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.

Note:

Pin names followed by '**' have 120 Kohm pull DOWN resistors

Pin names followed by '*' have 120 Kohm pull UP resistors