ICS345

MDS 345 D

1

Revision 090704

Integrated Circuit Systems, Inc.

Triple PLL Field Programmable SS VersaClock Synthesizer

Description

The ICS345 field programmable clock synthesizer

generates up to nine high-quality, high-frequency clock

outputs including multiple reference clocks from a

low-frequency crystal or clock input. It is designed to

replace crystals and crystal oscillators in most

electronic systems.

and outputs, the ICS345 contains a One-Time

Programmable (OTP) ROM to allow field

programmability. Programming features include eight

selectable configuration registers, up to two sets of four

low-skew outputs, and optional Spread Spectrum

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 ICS345 is also available in factory programmed

custom versions for high-volume applications.

Features

clocks, see the ICS342. For three output clocks, see

the ICS343. For more than three outputs, see the

ICS345 or ICS348.

Block Diagram

C rystal

O scillator

PLL1 with

Spread

Spec trum

GN D

2

3

VDD

PD TS

PLL2

PLL3

Divide

Logic

and

Output

Enable

Control

S2:S 0

CLK1

CLK9

CLK8

CLK7

CLK6

CLK5

CLK4

CLK3

CLK2

3

OT P

RO M

with

PLL

Values

X2

C rystal or

cloc k input

E xternal capacitors are

required w ith a crystal input.

X1/ICLK