IDT®

Low Power Clock for Intel Atom®-Based Systems

1561C — 08/24/11

9LPRS436C

Low Power Clock for Intel Atom

®-Based Systems

4

Pin Description (Continued)

25

GND

PWR

Ground pin.

26

VDDPCIEX

PWR

Power supply for PCI Express clocks, nominal 3.3V

27

CPUITPC_LR2/PCIeC_LR2

OUT

Complementary clock of differential pair CPU output. / Complementary clock of

differential PCIEX pair. These are 0.8V push pull outputs. No external 50ohm

resistor to GND or 33ohm series resistor needed.

28

CPUITPT_LR2/PCIeT_LR2

OUT

True clock of differential pair CPU output. / True clock of differential PCIEX

pair. These are 0.8V push pull outputs. No external 50ohm resistor to GND or

33ohm series resistor needed.

29

CPUC_LR1

OUT

Complementary clock of differential pair 0.8V push-pull CPU outputs with

integrated 33ohm series resistor.

30

CPUT_LR1

OUT

True clock of differential pair 0.8V push-pull CPU outputs with integrated

33ohm series resistor.

31

VDDCPU

PWR

Supply for CPU clocks, 3.3V nominal

32

CPUC_LR0

OUT

Complementary clock of differential pair 0.8V push-pull CPU outputs with

integrated 33ohm series resistor.

33

CPUT_LR0

OUT

True clock of differential pair 0.8V push-pull CPU outputs with integrated

33ohm series resistor.

34

GND

PWR

Ground pin.

35

SCLK

IN

Clock pin of SMBus circuitry, 5V tolerant.

36

SDATA

I/O

Data pin for SMBus circuitry, 5V tolerant.

37

CPU_STOP#

IN

Stops CPU0 clock when enabled.

38

PCI&PCIEX_STOP#

IN

Stops all PCICLKs at logic 0 level, when low. Free running PCICLKs are not

effected by this input.

39

X2_25

OUT

Crystal output, Nominally 25.00MHz.

40

X1_25

IN

Crystal input, Nominally 25.00MHz.

41

GND

PWR

Ground pin.

42

25MHz

OUT

25MHz clock output, 3.3V

43

VDDSUSP

PWR

Supply for suspend mode, powers 25MHz PLL, 25M output and XTAL

oscillator. 3.3V Nominal

44

Vtt_PwrGd/WOL_STOP#

IN

This active high 3.3V LVTTL input is a level sensitive strobe used to determine

when latch inputs are valid and are ready to be sampled / Asynchronous active

low input pin that stops all outputs except free running 25Mhz

45

VDD14

PWR

Power for 14.31818MHz PLL and REF output, nominal 3.3V.

46

REF0_2x/FSLC

I/O

2x strength 14.318 MHz reference clock./ 3.3V tolerant input for CPU frequency

selection. Refer to input electrical characteristics for Vil_FS and Vih_FS

values.

47

GND

PWR

Ground pin.

48

GND

PWR

Ground pin.