Integrated

Circuit

Systems, Inc.

General Description

Features

ICS9112-43/44

Block Diagram

Frequency Generator for Gigabit Ethernet Systems

Applications

9112-43 9112-44 Rev D 3/3/99

The ICS9112-43/44 is a high speed clock generator designed

to support Gigabit Ethernet system requirements. The

ICS9112-43/44 generates 125 MHz from a 20 MHz crystal.

An exact frequency multiplying ratio ensures better than

±100 ppm frequency accuracy using a standard AT crystal

with external load capacitors (typically 33pF±5% for an

18pF load crystal). Achieving ±100 ppm over four years

requires the crystal to have a ±20 ppm initial accuracy, ±30

ppm temperature and ±5 ppm/year aging coefficients.

The ICS9112-43/44 with less than 50ps accumulative jitter

is well suited for Gigabit Ethernet applications.

•

Generates 125 MHz clocks from a 20 MHz crystal

•

Less than 45ps one sigma jitter (15ps typ.)

•

Less than ±130ps absolute jitter

•

Less than 50ps accumulative jitter @ 256 cycles

•

Rise/fall times less than 1.2ns driving 15pF

•

On-chip loop filter components

•

3.0V-5.5V supply range

•

8-pin, 150-mil SOIC package

•

Specifically designed to support the high-speed

clocking requirements of Gigabit Ethernet systems.

PRODUCT PREVIEW documents contain information on new

products in the sampling or preproduction phase of development.

Characteristic data and other specifications are subject to change

without notice.

Preliminary Product Preview