844004AGI-01

www.icst.com/products/hiperclocks.html

REV. A JUNE 15, 2005

1

Integrated

Circuit

Systems, Inc.

ICS844004I-01

PRELIMINARY

The ICS844004I-01 is a 4 output LVDS Synthesizer

optimized to generate Ethernet reference clock

family of high performance 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_SEL[1:0]): 156.25MHz, 125MHz and

low phase noise VCO technology and can achieve <1ps

typical rms phase jitter, easily meeting Ethernet jitter

requirements. The ICS844004I-01 is packaged in a small 24-

pin TSSOP package.

• Four LVDS outputs

• Selectable crystal oscillator interface

or LVCMOS/LVTTL single-ended input

• Supports the following output frequencies: 156.25MHz,

125MHz, 62.5MHz

• VCO range: 560MHz - 680MHz

• RMS phase jitter @ 156.25MHz, using a 25MHz crystal

(1.875MHz - 20MHz): 0.41ps (typical)

• Full 3.3V or 2.5V supply modes

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

HiPerClockS™

ICS

1

1

0

1

0

Phase

Detector

VCO

625MHz

(w/25MHz

Reference)

M = 25 (fixed)

F_SEL[1:0]

0 0

÷4

0 1

÷5

1 0

÷10

1 1

not used

2

OSC

ICS844004I-01

24-Lead TSSOP

4.40mm x 7.8mm x 0.92mm

package body

G Package

Top View

nQ1

Q1

Q0

nQ0

MR

nPLL_SEL

nc

F_SEL0

F_SEL1

1

2

3

4

5

6

7

8

9

10

11

12

nQ2

Q2

Q3

nQ3

GND

nXTAL_SEL

TEST_CLK

GND

XTAL_IN

XTAL_OUT

24

23

22

21

20

19

18

17

16

15

14

13

t

u

p

t

u

O

y

c

n

e

u

q

e

r

F

)

.

f

e

R

z

H

M

5

2

(

1

L

E

S

_

F0

L

E

S

_

F

r

e

d

i

v

i

D

M

e

u

l

a

V

r

e

d

i

v

i

D

N

e

u

l

a

V

r

e

d

i

v

i

D

N

/

M

e

u

l

a

V

00

5

24

5

2

.

65

.

6

5

1

01

5

25

5

5

2

1

10

5

20

15

.

25

.

2

6

11

5

2d

e

s

U

t

o

Nd

e

s

U

t

o

N

F_SEL[1:0]

nPLL_SEL

TEST_CLK

XTAL_IN

XTAL_OUT

nXTAL_SEL

MR

Q0

nQ0

Q1

nQ1

Q2

nQ2

Q3

nQ3

Pulldown

Pulldown

25MHz

Pulldown

Pulldown

Pulldown

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.