ICS271

MDS 271 A

1

Revision 040705

Integrated Circuit Systems, Inc.

Triple PLL Field Programmable VCXO Clock Synthesizer

PRELIMINARY INFORMATION

Description

The ICS271 field programmable VCXO clock

synthesizer generates up to six high-quality,

high-frequency clock outputs including multiple

reference clocks from a low-frequency crystal input. It

is designed to replace crystals and crystal oscillators in

most electronic systems.

and outputs, the ICS271 contains a One-Time

Programmable (OTP) ROM for field programmability.

Programming features include VCXO, eight selectable

configuration registers and up to two sets of three

low-skew outputs.

Each of the two output groups are powered by a

separate VDDO voltage. VDDO may vary from 1.8 V to

VDD.

Using Phase-Locked Loop (PLL) techniques, the

device runs from a standard fundamental mode,

inexpensive crystal, or clock. It can replace VCXOs,

multiple crystals and oscillators, saving board space

and cost.

The ICS271 is also available in factory programmed

custom versions for high-volume applications.

Features

each bank of 3 outputs

Block Diagram

Voltage

Controlled

Crystal

Oscillator

GND

2

3

VDD

PDTS

PLL2

PLL3

Divide

Logic

and

Output

Enable

Control

S2:S0

CLK1

CLK6

CLK5

CLK4

CLK3

CLK2

3

OTP

ROM

with

PLL

Values

X2

Crystal

External capacitors

are required.

X1

PLL1

VIN

VDDO1

VDDO2