Integrated

Circuit

Systems, Inc.

General Description

Features

ICS9148-32

Block Diagram

9148-32 Rev B 09/09/98

Pin Configuration

48-Pin SSOP

Pentium is a trademark on Intel Corporation.

•

Generates system clocks for CPU, IOAPIC, PCI,

14.314 MHz REF , USB, and Super I/O

•

Supports single or dual processor systems

•

Supports Spread Spectrum modulation for CPU & PCI

clocks, ±0.255% Center Spread or 0 to -0.6% Down

Spread.

•

Skew from CPU (earlier) to PCI clock 1 to 4ns

•

CPU cycle to cycle jitter ±200ps

•

2.5V or 3.3V output: CPU, IOAPIC

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3.3Voutputs: PCI, REF, 48MHz

•

No power supply sequence requirements

•

Uses external 14.318MHz crystal, no external load cap

•

48pin300milSSOP

The ICS9148-32 is a Clock Synthesizer chip for Pentium and

PentiumPro CPU based Desktop/Notebook systems that will

provide all necessary clock timing.

Features include four CPU and eight PCI clocks. Three

reference outputs are available equal to the crystal frequency.

Additionally, the device meets the Pentium power-up

stabilization requirement, assuring that CPU and PCI clocks

are stable within 2ms after power-up.

PD# pin enables low power mode by stopping crystal OSC

and PLL stages. Other power management features include

CPU_STOP#, which stops CPU (0:3) clocks, and PCI_STOP#,

which stops PCICLK (0:6) clocks.

disabling.

High drive CPUCLK outputs typically provide greater than 1

V/ns slew rate into 20pF loads. PCICLK outputs typically

provide better than 1V/ns slew rate into 30pF loads while

maintaining 50±5% duty cycle. The REF clock outputs typically

provide better than 0.5V/ns slew rates.

The ICS9148-32 accepts a 14.318MHz reference crystal or

clock as its input and runs on a 3.3V core supply.

Power Groups

VDD = Supply for PLL core

VDD1=REF(0:2),X1,X2

VDD2=PCICLK_F,PCICLK(0:6)

VDD3=48MHz,24/48MHz#

VDDL1=IOAPIC(0:1)

VDDL2=CPUCLK(0:3)

Ground Groups

GND = Ground for PLL core

GND1=REF(0:2),X1,X2

GND2=PCICLK_F,PCICLK(0:6)

GND3=48MHz,24/48MHz#

GNDL1=IOAPIC(0:1)

GNDL2=CPUCLK(0:3)

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.