Integrated

Circuit

Systems, Inc.

840004AGI-01

www.icst.com/products/hiperclocks.html

REV. A JUNE 28, 2005

1

ICS840004I-01

PRELIMINARY

The ICS840004I-01 is a 4 output LVCMOS/LVTTL

Synthesizer optimized to generate Ethernet

reference clock frequencies and is a member of

clock solutions from ICS. Using a 25MHz, 18pF

parallel resonant crystal, the following frequencies can be

generated based on the 2 frequency select pins (F_SEL1:0):

156.25MHz, 125MHz, and 62.5MHz. The ICS840004I-01 uses

achieve 1ps or lower typical random rms phase jitter, easily

meeting Ethernet jitter requirements. The ICS840004I-01 is

packaged in a small 20-pin TSSOP package.

HiPerClockS™

ICS

• Four LVCMOS/LVTTL outputs, 15

Ω typical output impedance

• Selectable crystal oscillator interface

or LVCMOS single-ended input

• Supports the following output frequencies:

156.25MHz, 125MHz and 62.5MHz

• RMS phase jitter @ 156.25MHZ (1.875MHz - 20MHz):

0.52ps (typical)

• Output supply modes:

Core/Output

3.3V/3.3V

3.3V/2.5V

2.5V/2.5V

• -40°C to 85°C ambient operating temperature

Q0

Q1

Q2

Q3

OE

F_SEL1:0

nPLL_SEL

nXTAL_SEL

XTAL_IN

XTAL_OUT

TEST_CLK

MR

OSC

Phase

Detector

VCO

M = ÷25 (fixed)

F_SEL1:0

0 0 ÷4

0 1 ÷5

1 0 ÷10

1 1 ÷5

0

1

1

0

2

N

25MHz

Pullup

Pulldown

Pulldown

Pulldown

Pullup:Pullup

Pulldown

ICS840004I-01

20-Lead TSSOP

6.5mm x 4.4mm x 0.92mm

package body

G Package

Top View

F_SEL0

nc

nXTAL_SEL

TEST_CLK

OE

MR

nPLL_SEL

nc

1

2

3

4

5

6

7

8

9

10

20

19

18

17

16

15

14

13

12

11

F_SEL1

GND

Q0

Q1

Q2

Q3

GND

XTAL_IN

XTAL_OUT

s

t

u

p

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)

z

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M

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q

e

r

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t

u

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O

)

.

f

e

R

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M

5

2

(

1

L

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S

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F0

L

E

S

_

F

r

e

d

i

v

i

D

M

e

u

l

a

V

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D

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a

V

N

/

M

e

u

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a

V

o

i

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a

R

00

5

24

5

2

.

65

2

.

6

5

1

01

5

25

5

5

2

1

10

5

20

15

.

25

.

2

6

11

5

25

5

5

2

1

The Preliminary Information presented herein represents a product in prototyping or pre-production. The noted characteristics are based on initial

product characterization. Integrated Circuit Systems, Incorporated (ICS) reserves the right to change any circuitry or specifications without notice.