ICST AV9169CF-46, ICS9169CF-46 Datasheet

Integrated
Circuit
Systems, Inc.

General Description Features

ICS9169C-46

Block Diagram

Frequency Generator for PentiumPro Based Systems

9169C-46RevA072597P

Pin Configuration

34-Pin SSOP

Pentium is a trademark on Intel Corporation.

 16 selectable CPU clocks up to 66.66 MHz
 One synchronous PCI clock.
 One USB clock at 48MHz, meets Intel jitter,

accuracy, as well as rise and fall time requirements
 One I/O clock at 24MHz
 One Ref. Clock at 14.318MHz
 CPU clocks to PCI clock skew of 1-4ns (CPU early)
 Low CPU and PCI clock jitter <200ps
 Low skew outputs, skew window 250ps for CPU

clocks and for PCI clocks
 Improved output drivers are designed for low EMI
 Test Mode
 3.3V ±10% operation
 Space saving and low cost 34-pin SSOP package

The ICS9169C-46 is a Clock Synthesize/Driver chip for
Pentium, PentiumPro or Cyrix 68x86 based motherboards
using SDRAM.

Features include sixteen CPU outputs, twelve of which can
be used to support up to three SDRAM modules. The
PCICLK output can be buffered with an external, low cost
zero delay buffer. Additionally, the device meets the
Pentium and PentiumPro power-up stabilization, which
requires that CPU and PCI clocks be stable within 2ms after
power-up.

The ICS9169C-46 clock outputs are designed for low EMI
emissions. Controlled rise and fall times, unique output
driver circuits and innovative circuit layout techniques enable
the ICS9169C-46 to have lower EMI than other clock
devices.

The ICS9169C-46 accepts a 14.318MHz reference crystal
or clock as its input and runs from a 3.3V supply.

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.

2

ICS9169C-46

Pin Descriptions

Functionality

3.3V±10%, 0-70°C
Crystal (X1, X2) = 14.31818 MHz

FS1 FS0 XTALIN

CPUCLK (0: 15)

(MHz)

PCICLK0

(MHz)

REF(0:1)

(MHz)

USBCLK

(MHz)

IOCLK

(MHz)

0 0 14.318MHz Hi-Z Hi-Z Hi-Z Hi-Z Hi-Z
0 1 14.318MHz 66.67 33.3 14.318 48 24
1 0 14.318MHz 50.0 25.0 14.318 48 24
1 1 14.318MHz 60.0 30.0 14.318 48 24

Actual Output Frequencies

Output Clocks

Target Frequency

(MHz)

Actual Frequency

(MHz)

CPUCLK (0:15) 50.0 48.83
CPUCLK (0:15) 60.0 60.0
CPUCLK (0:15) 66.67 68.66

USBCLK 48 48.008

IOCLK 24 24.004

PIN NUMBER PIN NAME TYPE DESCRIPTION

1, 8, 14, 26, 32 V

DD

PWR Voltage Supply
2 X1 IN Reference crystal input
3 X2 OUT Reference crystal feedbac k

4, 11 20, 23, 29 GND PWR Ground

5, 6, 7, 9, 10, 12,

13, 16, 17, 18, 19,

21, 22, 24, 25, 27

CPUCLK(0:15) OUT CPU clock outputs

15, 34 FS (0:1) IN CPU clock select input bits. These devices have internal pull-ups

28 PCICLK OUT BUS cl ock output
30 USBCLK OUT USB clock out put 48 MHz

31 IOCLK OUT I/O cloc k output 24 MHz
33 REF0 OUT Reference clock output (14.318 MHz)