CS5530 Geode
™
Description
The MK1491-06 is a low cost, low jitter, high
performance clock synthesizer for National
Semiconductor CS5530 based computer and
portable appliance applications. Using patented
analog Phase-Locked Loop (PLL) techniques,
the device accepts a 14.318 MHz crystal input to
produce multiple output clocks. It provides
selectable PCI local bus and AC97 audio clocks,
24 MHz and 48 MHz clocks for Super I/O and
USB, as well as multiple Reference outputs.
The device has multiple power down modes to
reduce power consumption.
MK1491-06
Clock Source
Features
• Packaged in 28 pin, 300 mil wide SOIC or in
28 pin, 150 mil wide SSOP
• Provides all critical timing for the National
Semiconductor CS5530 Geode companion chip
• Four PCI clocks
• Selectable PCIF on up to 2 outputs
• Early PCI clock selectability
• Up to 4 Reference clocks
• 48 MHz USB and 24MHz SIO support
• AC97 audio clock
• Multiple power down modes
• Low EMI Enable pin reduces EMI radiation on
PCI clocks (patented)
• 3.3 V ±5% operation
Block Diagram
VDD
6
GND
5
2
Output
Buffers
PCI
Clocks
PCI Frequency Select
Low EMI Enable
PCIF Function Enable
Early PCI Enable
SLOW#
PCISTP#
PWRDWN#
3
PCI
Output
Buffer
EPCI/PCI
Audio Select
Audio
Clock
Fixed
Clocks
Output
Buffer
Output
Buffer
Output
Buffer
Output
Buffers
3
16.934 MHz or
24.576 MHz or
49.152 MHz
48 MHz
14.318 MHz or
24 MHz
14.3M/24M Select
XI
14.31818 MHz
crystal
XO
Crystal
Oscillator
MUX
14.318 MHz
MDS 1491-06 F
1
Revision 101700
Printed 11/15/00
Integrated Circuit Systems, Inc. • 525 Race Street • San Jose • CA • 95126 • (408)295-9800tel • www.icst.com
ICS [ INTEGRATED CIRCUIT SYSTEMS ]
