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

1542E 12/16/10

ICS9FG108D

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

vSPREAD

IN

Asynchronous, active high input to enable spread spectrum functionality. This pin has

a 120Kohm pull down resistor.

27

^SEL14M_25M#

IN

Select 14.31818 MHz or 25 Mhz input frequency. This pin has an internal 120kohm

pull up resistor.

1 = 14.31818 MHz, 0 = 25 MHz

28

vOE_3

IN

Active high input for enabling output 3. This pin has an internal 120kohm pull down

resistor.

0 = tri-state outputs, 1= enable outputs

29

DIF_3#

OUT

0.7V differential Complementary 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 Complementary clock output

33

DIF_2

OUT

0.7V differential true clock output

34

^OE_2

IN

Active high input for enabling output 2. This pin has in internal 120kohm pull up

resistor.

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. This pin has an internal 120kohm pull up

resistor.

0 = tri-state outputs, 1= enable outputs

38

DIF_1#

OUT

0.7V differential Complementary 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 Complementary clock output

42

DIF_0

OUT

0.7V differential true clock output

43

vOE_0

IN

Active high input for enabling output 0. This pin has an internal 120kohm pull down

resistor.

0 = tri-state outputs, 1= enable outputs

44

vFS1

IN

3.3V Frequency select latched input pin with internal 120kohm pull down resistor.

45

vFS0

IN

3.3V Frequency select latched input pin with internal 120kohm pull down resistor.

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:

^ indicates internal 120K pull up

v indicates internal 120K pull down