ICS650-01

System Peripheral Clock Source

MDS 650-01 C

1

Revision 092799

Printed 11/15/00

Integrated Circuit Systems • 525 Race Street • San Jose •CA•95126• (408) 295-9800tel • (408) 295-9818fax

The ICS650-01 is a low cost, low jitter, high

performance clock synthesizer for system

peripheral applications. Using analog/digital

Phase-Locked Loop (PLL) techniques, the device

accepts a parallel resonant 14.31818 MHz crystal

input to produce up to eight output clocks. The

device provides clocks for PCI, SCSI, Fast

Ethernet, Ethernet, USB, and AC97. The user can

select one of three USB frequencies, and also one

of three AC97 audio frequencies. The OE pin puts

all outputs into a high impedance state for board

level testing. All frequencies are generated with less

than one ppm error, meeting the demands of SCSI

and Ethernet clocking.

The ICS650 can be mask customized to produce

any frequencies from 1 to 150 MHz.

Block Diagram

Description

Features

• Packaged in 20 pin tiny SSOP (QSOP)

• Operating VDD of 3.3V or 5V

• Less than one ppm synthesis error in all clocks

• Inexpensive 14.31818 MHz crystal or clock input

• Provides Ethernet and Fast Ethernet clocks

• Provides SCSI clocks

• Provides PCI clocks

• Selectable AC97 audio clock

• Selectable USB clock

• OE pin tri-states the outputs for testing

• Selectable frequencies on three clocks

• Duty cycle of 40/60

• Advanced, low power CMOS process

Crystal

Oscillator

Clock

Synthesis

Circuitry

Output

Buffer

USB Clock

Output

Buffers

Audio Clock

Processor Clocks

(Fast Ethernet,

SCSI, PCI )

Output

Buffer

2

PSEL1:0

14.31818 MHz

crystal

or clock

X1/ICLK

X2

14.31818 MHz

Output

Buffer

4

ASEL

USEL

20 MHz

Output

Buffers

Output Enable (all outputs)