ICS841402I Data Sheet

FEMTOCLOCK® CRYSTAL-TO-0.7V DIFFERENTIAL HCSL CLOCK GENERATOR

ICS841402DKI REVISION A NOVEMBER 7, 2012

2

©2012 Integrated Device Technology, Inc.

Table 1. Pin Descriptions

NOTE: Pulldown and Pullup refer to internal input resistors. See Table 2, Pin Characteristics, for typical values.

Table 2. Pin Characteristics

Number

Name

Type

Description

1,

2

XTAL_IN,

XTAL_OUT

Input

Parallel resonant crystal interface. XTAL_OUT is the output,

XTAL_IN is the input. (PLL reference.)

3

MR/nOE

Input

Pulldown

Master reset. LVCMOS/LVTTL interface levels. See Table 3D.

4, 14, 24, 29

VDD

Power

Core supply pins.

5, 6

Q0, nQ0

Output

Differential output pair. HCSL interface levels.

7, 8

Q1, nQ1

Output

Differential output pair. HCSL interface levels.

9, 19, 32

GND

Power

Power supply ground.

10, 11, 12,

13, 15, 16,

17, 18

nc

Unused

No connect.

20

OE_REFOUT

Input

Pulldown

Output enable pin. LVCMOS/LVTTL interface levels. See Table 3F.

21

REF_OUT

Output

Reference clock output. LVCMOS/LVTTL interface levels. In PCIe Gen 2

and Gen 3 applications, the REF_OUT output should be disabled.

22

F_SEL0

Input

Pulldown

Output frequency select pin. LVCMOS/LVTTL interface levels.

See Table 3B.

23

F_SEL1

Input

Pullup

Output frequency select pin. LVCMOS/LVTTL interface levels.

See Table 3B.

25

SSM

Input

Pulldown

Spread-spectrum selection. LVCMOS/LVTTL interface levels.

See Table 3A.

26

IREF

Output

0.7V current reference resistor output. A fixed precision resistor (475

)

from this pin to ground provides a reference current used for differential

current-mode Qx, nQx clock outputs.

27

BYPASS

Input

Pulldown

Selects PLL operation/PLL bypass operation. See Table 3C.

LVCMOS/LVTTL interface levels.

28

VDDA

Power

Analog supply pin.

30

REF_SEL

Input

Pulldown

Reference select. Selects the input reference source.

LVCMOS/LVTTL interface levels. See Table 3E.

31

REF_IN

Input

Pulldown

LVCMOS/LVTTL PLL reference clock input.

Symbol

Parameter

Test Conditions

Minimum

Typical

Maximum

Units

CIN

Input Capacitance

4

pF

RPULLDOWN

Input Pulldown Resistor

51

k



RPULLUP

Input Pullup Resistor

51

k



ROUT

Output

Impedance

REF_OUT

27

