844003AGI

www.icst.com/products/hiperclocks.html

REV. B AUGUST 25, 2005

1

Integrated

Circuit

Systems, Inc.

ICS844003I

PRELIMINARY

The ICS844003I is a 3 differential output LVDS

Synthesizer designed to generate Ethernet refer-

ence clock frequencies and is a member of the

HiPerClocks™ family of high performance clock

solutions from ICS. Using a 31.25MHz or

26.041666MHz, 18pF parallel resonant crystal, the following

frequencies can be generated based on the settings of 4 fre-

quency select pins (DIV_SEL[A1:A0], DIV_SEL[B1:B0]):

625MHz, 312.5MHz, 156.25MHz, and 125MHz. The 844003I

has 2 output banks, Bank A with 1 differential LVDS output

pair and Bank B with 2 differential LVDS output pairs.

The two banks have their own dedicated frequency se-

lect pins and can be independently set for the frequen-

cies mentioned above. The ICS844003I uses ICS’ 3rd gen-

eration low phase noise VCO technology and can achieve

1ps or lower typical rms phase jitter, easily meeting

Ethernet jitter requirements. The ICS844003I is packaged

in a small 24-pin TSSOP package.

• Three LVDS outputs on two banks, A Bank with one LVDS

pair and B Bank with 2 LVDS output pairs

• Using a 31.25MHz or 26.041666MHz crystal, the two

output banks can be independently set for 625MHz,

312.5MHz, 156.25MHz or 125MHz

• Selectable crystal oscillator interface or LVCMOS/LVTTL

single-ended input

• VCO range: 560MHz to 700MHz

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

0.63ps (typical)

• 3.3V output supply mode

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

• Available in both standard and lead-free RoHS-compliant

packages

HiPerClockS™

ICS

0

1

0

1

Phase

Detector

VCO

560-700MHz

0 = ÷20 (default)

1 = ÷24

0 0

÷1

0 1

1 0

÷4

1 1

÷5

0 0

÷1

0 1

÷2

1 0

1 1

÷5

FB_DIV

OSC

CLK_ENA

DIV_SELA[1:0]

VCO_SEL

TEST_CLK

XTAL_IN

XTAL_OUT

XTAL_SEL

FB_DIV

DIV_SELB[1:0]

MR

CLK_ENB

QA0

nQA0

QB0

nQB0

QB1

nQB1

Pulldown

Pulldown

Pullup

Pullup

Pullup

Pullup

ICS844003I

24-Lead TSSOP

4.40mm x 7.8mm x 0.92mm

package body

G Package

Top View

DIV_SELB0

VCO_SEL

MR

QA0

nQA0

CLK_ENB

CLK_ENA

FB_DIV

DIV_SELA0

1

2

3

4

5

6

7

8

9

10

11

12

DIV_SELB1

QB0

nQB0

QB1

nQB1

XTAL_SEL

TEST_CLK

XTAL_IN

XTAL_OUT

GND

DIV_SELA1

24

23

22

21

20

19

18

17

16

15

14

13

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.