SM8702AM 参数 Datasheet PDF下载

SM8702AM

NIPPON PRECISION CIRCUITS INC.

Clock Generator IC

OVERVIEW

The SM8702AM is a clock generator IC that can generate clock signals up to and exceeding 100MHz for per-

sonal computer (PC) motherboards. It uses a single 14.318MHz crystal oscillator element and 2 built-in PLLs

to simultaneously and independently generate 2 CPU clocks, 6 PCI bus clocks, 2 reference clocks with the

same frequency as the crystal element, 48MHz USB interface clock, and 24MHz Super I/O chip clock outputs.

It also has 14 outputs that can function as SDRAM clocks by buffering an external input SDRAM clock.

FEATURES

s

PINOUT

s

s

s

s

s

s

s

s

s

lim

s

s

pre

s

Intel

®

Pentium

®

II, Pentium

®

III, and AMD x86-

compatibles supported

2.5/3.3V CPU clock outputs and IOAPIC clock

output

14

×

SDRAM clock outputs (3 DIMMs)

2

×

CPU clock outputs

(60), 66, 75, 83, 95, 100, 103, 112, (124), 133MHz

CPU/SDRAM clock frequencies. Values in paren-

theses are available as mask options.

6

×

PCI bus clock outputs (one free-running out-

put)

33MHz or 1/2, 1/3, 1/4 of the CPU clock fre-

quency

2

×

reference clock outputs and 1

×

IOAPIC clock

output

14.318MHz REF/IOAPIC clock frequency

1

×

48MHz USB interface clock output

1

×

24MHz clock output for Super I/O chip

I

2

C serial data bus for frequency/mode output con-

trol

CPU-stop and PCI-stop functions

Spread Spectrum Clock Generator (SSCG) out-

puts

Center spread/Down spread, ± 0.5% or ± 1.5%

3.3V (VDD) and 2.5/3.3V (VDDL) supply volt-

ages

48-pin SSOP package (pin compatible with

ICS9148-26)

48-pin SSOP (300 mil)

ina

(Top view)

VDD1

REF0

VSS

XT

XTN

VDD2

PCICLK_F/MODE

PCICLK0

VSS

PCICLK1

PCICLK2

PCICLK3

PCICLK4

VDD2

BUFFERIN

VSS

SDRAM11/CPU_STOP#

SDRAM10/PCI_STOP#

VDD3

SDRAM9

SDRAM8

VSS

SDATA

SCLK

1

24

ORDERING INFORMATION

D e vice

SM8702AM

P ackag e

48-pin SSOP

APPLICATIONS

s

PC motherboards using Intel

®

Pentium

®

, Pen-

tium

®

II/III, AMD-K6 devices, and x86 architec-

ture CPUs

Intel

®

and Pentium

®

are registered trademarks of Intel co..

AMD and AMD-K6 are registered trademarks of Advanced Micro Devices, Inc..

I

2

C Bus is a registered trademark of Philips Electronics N. V..

ry

48

25

VDDL1

IOAPIC

REF1/FS2

VSS

CPUCLK0

CPUCLK1

VDDL2

SDRAM13

SDRAM12

VSS

SDRAM0

SDRAM1

VDD3

SDRAM2

SDRAM3

VSS

SDRAM4

SDRAM5

VDD3

SDRAM6

SDRAM7

VDD4

48MHz/FS0

24MHz/FS1

NIPPON PRECISION CIRCUITS—1

SM8702AM