ICS290

MDS 290 C

1

Revision 062305

Integrated Circuit Systems, Inc.

Triple PLL Field Prog. Spread Spectrum Clock Synthesizer

PRELIMINARY INFORMATION

Description

The ICS290 field programmable spread spectrum

clock synthesizer generates up to eight high-quality,

high-frequency clock outputs including multiple

reference clocks from a low-frequency crystal input. It

is designed to replace crystals, crystal oscillators and

stand alone spread spectrum devices in most

electronic systems.

and outputs, the ICS290 contains a One-Time

Programmable (OTP) ROM for field programmability.

Programming features include input/output

frequencies, spread spectrum amount, eight selectable

configuration registers and up to two sets of four

low-skew outputs.

Using Phase-Locked Loop (PLL) techniques, the

device runs from a standard fundamental mode,

inexpensive crystal, or clock. It can replace multiple

crystals and oscillators, saving board space and cost.

The ICS290 is also available in factory programmed

custom versions for high-volume applications.

Features

Block Diagram

Crystal

Oscillator

GND

3

3

VDD

PDTS

PLL2

PLL3

Divide

Logic

and

Output

Enable

Control

S2:S0

CLK1

CLK8

CLK7

CLK6

CLK5

CLK4

CLK3

CLK2

3

OTP

ROM

with PLL

Values

X2

Crystal or

Clock Input

External capacitors

are required with a crystal input.

X1/ICLK

PLL1 with

Spread

Spectrum