ICS650-01B
System Peripheral Clock Source
Description
The ICS650-01B is a low cost, low jitter, high
performance clock synthesizer for system
peripheral applications. Using analog/digital
Phase-Locked Loop (PLL) techniques, the device
accepts a parallel resonant 14.31818 MHz crystal
input to produce up to eight output clocks. The
device provides clocks for PCI, SCSI, Fast
Ethernet, Ethernet, and AC97. The user can select
from multiple interface frequencies, and also one
of three AC97 audio frequencies. The OE pin puts
all outputs into a high impedance state for board
level testing. All frequencies are generated with less
than one ppm error, meeting the demands of SCSI
and Ethernet clocking.
The ICS650 can be mask customized to produce
any frequencies from 1 to 150 MHz.
Features
• Packaged in 20 pin tiny SSOP (QSOP)
ª Operating VDD of 3.3V or 5V
• Less than one ppm synthesis error in all clocks
• Inexpensive 14.31818 MHz crystal or clock input
• Provides Ethernet and Fast Ethernet clocks
• Provides SCSI clocks
• Provides PCI clocks
• Selectable AC97 audio clock
• Selectable interface clock
• OE pin tri-states the outputs for testing
• Selectable frequencies on three clocks
• Duty cycle of 40/60
• Advanced, low power CMOS process
Block Diagram
4
Processor Clocks
(Fast Ethernet,
SCSI, PCI )
Audio Clock
B Clock 1
B Clock 2
14.31818 MHz
PSEL1:0
ASEL
BSEL
14.31818 MHz
crystal
X1
2
Output
Buffer
Clock
Synthesis
Circuitry
Output
Buffer
Output
Buffer
Output
Buffer
Crystal
Oscillator
X2
Output
Buffer
Output Enable (all outputs)
1
Revision 041499
Printed 11/15/00
Integrated Circuit Systems • 525 Race Street • San Jose •CA•95126• (408) 295-9800tel • (408) 295-9818fax
MDS 650-01B A
ICS [ INTEGRATED CIRCUIT SYSTEMS ]
