MK1491-09
AMD Geode™ GX2 Clock Source
Description
The MK1491-09 is a low-cost, low-jitter,
high-performance clock synthesizer for AMD’s
Geode-based computer and portable appliance
applications. Using patented analog Phased-Locked
Loop (PLL) techniques, the device accepts a 14.318
MHz crystal input to produce multiple output clocks. It
provides selectable PCI local bus clocks, 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.
Features
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Packaged in 28-pin SSOP (209 mil body)
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Available in Pb (lead) free packaged
•
Provides all critical timing for the AMD Geode
companion chip
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Four selectable PCI clocks
Three LPC interface clocks
One Fixed 66 MHz clock
2 Reference clocks
48 MHz USB and 48 MHz IO support
Power down mode
Low EMI Enable pin reduces EMI radiation on PCI
clocks, LCLKS, and 66 MHz clock
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Operating voltage of 3.3 V ±5%
Block Diagram
VDD
6
GND
6
Sel66/33#
4
3
PCI (66/33 MHz)
LCLK (33 MHz)
66 MHz
Clocks
PD#
USB
Clock
48/TS#
48 MHz
REFCLK1
XI
14.31818 MHz
crystal
Crystal
Oscillator
REFCLK0/Spread#
XO
MDS 1491-09 G
Integrated Circuit Systems, Inc.
●
1
525 Race Street, San Jose, CA 95126
●
Revision 080204
tel (408) 297-1201
●
www.icst.com
ICS [ INTEGRATED CIRCUIT SYSTEMS ]
