ICS841664AGI REVISION A JULY 15, 2013

2

©2013 Integrated Device Technology, Inc.

ICS841664I Data Sheet

FEMTOCLOCK® CRYSTAL-TO-HCSL CLOCK GENERATOR

Pin Description and Pin Characteristic Tables

Table 1. Pin Descriptions

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

Table 2. Pin Characteristics

Number

Name

Type

Description

1, 18

VDD

Power

Core supply pins.

2

REF_OUT

Output

LVCMOS/LVTTL reference frequency clock output.

3, 7, 15, 22

GND

Power

Power supply ground.

4, 5,

8, 9

QA0, nQA0

QA1, nQA1

Output

Differential Bank A output pairs. HCSL interface levels.

6VDDOA

Power

Output supply pin for Bank A outputs.

10

nREF_OE

Input

Pullup

Active low REF_OUT enable/disable. See Table 3E.

LVCMOS/LVTTL interface levels.

11

BYPASS

Input

Pulldown

Selects PLL/PLL bypass mode. See Table 3C. LVCMOS/LVTTL interface levels.

12

REF_IN

Input

Pulldown

LVCMOS/LVTTL reference clock input.

13

REF_SEL

Input

Pulldown

Reference select, Selects the input reference source. See Table 3B.

LVCMOS/LVTTL interface levels

14

VDDA

Power

Analog supply pin.

16,

17

XTAL_OUT,

XTAL_IN

Input

Parallel resonant crystal interface. XTAL_OUT is the output,

XTAL_IN is the input.

19

MR/nOE

Input

Pulldown

Active HIGH master reset. Active LOW output enable. When logic HIGH, the

internal dividers are reset and the outputs are in high impedance. When logic

LOW, the internal dividers and the outputs are enabled. See Table 3D.

LVCMOS/LVTTL interface levels.

20, 21,

24, 25

nQB1, QB1

nQB0, QB0

Output

Differential Bank B output pairs. HCSL interface levels.

23

VDDOB

Power

Output supply pin for Bank B outputs.

26,

27

FSEL1,

FSEL0

Input

Pulldown

Output frequency select pins. LVCMOS/LVTTL interface levels.

28

IREF

Output

HCSL current reference resistor output. A fixed precision resistor (475

) form this

pin to ground provides a reference current used for differential current-mode

QX[0:1], nQX[0:1] clock outputs.

Symbol

Parameter

Test Conditions

Minimum

Typical

Maximum

Units

CIN

Input Capacitance

4pF

CPD

Power Dissipation Capacitance

VDD = 3.465V

4

pF

RPULLUP

Input Pullup Resistor

51

k



RPULLDOWN

Input Pulldown Resistor

51

k



ROUT

Output Impedance

REF_OUT

VDD = 3.465V

20

