Integrated

Circuit

Systems, Inc.

General Description

Features

ICS9169C-40

Block Diagram

System Clock Chip

9169C-40RevA072897P

Pin Configuration

34-Pin SSOP

Functionality

Crystal (X1, X2) = 14.31818 MHz

Pentium is a trademark on Intel Corporation.

•

8 selectable CPU clocks up to 75MHz

•

Six synchronous PCI clocks

•

One Referance Clock at 14.318MHz

•

Power-up stabilization time = 2ms on all CPU and PCI

clocks, which meets Intel PentiumPro power-up

•

Low CPU and PCI clock jitter <500ps

•

Low skew output

•

Improved output drivers are designed for low EMI

•

Test Mode

•

Optional common or mixed supply mode:

(VDD=VDDL1=VDDL2=3.3V)

(VDD=3.3V,VDDL1=VDDL2=2.5)

(VDD=3.3V,VDDL1=3.3V,VDDL2=2.5V)

•

Space saving and low cost 34-pin SSOP package

The ICS9169C-40 is a Clock Synthesizer chip for Pentium or

Cyrix CPU based motherboards using PCI.

Features include eight CPU clocks and six PCI clocks. A

Reference Output is available equal to the crystal frequency.

The device meets the Pentium power-up stabilization, which

requires that CPU and PCI clocks be stable within 2ms after

power-up.

The ICS9169C-40 clock output are designed for low EMI

emissions. Controlled rise and fall times, unique output

driver circuits and innovative circuit layout techniques enable

the ICS9169C-40 to have lower EMI than other clock

devices.

The ICS9169C-40 accepts a 14.318MHz reference crystal or

clock as its input and runs from a 3.3V supply.

FS2

FS1

FS0

CPU

PCI

0

0

0

50MHz

33.3MHz

0

0

1

55MHz

36.67MHz

0

1

0

REF/2

REF/4

0

1

1

75MHz

37.5MHz

1

0

0

50MHz

25MHz

1

0

1

55MHz

27.6MHz

1

1

0

60MHz

30MHz

1

1

1

66.6MHz

33.3MHz

ICS reserves the right to make changes in the device data identified in this

publication without further notice. ICS advises its customers to obtain the latest

version of all device data to verify that any information being relied upon by the

customer is current and accurate.