Integrated
Circuit
Systems, Inc.
ICS9159C-14
Frequency Generator and Integrated Buffer for PENTIUM™
General Description
The
ICS9159C-14
generates all clocks required for high
speed RISC or CISC microprocessor systems such as 486,
Pentium, PowerPC,™ etc. Four different reference frequency
multiply-ing factors are externally selectable with smooth
frequency transitions. These multiplying factors can be
customized for specific applications. It has a TURBO pin
that can speed up the 60 and 66.6 MHz clocks by 2.5%.
High drive BCLK outputs provide typically greater than 1V/
ns slew rate into 30pF loads. PCLK outputs provide typically
better than 1V/ns slew rate into 20pF loads while maintaining
50±5% duty cycle.
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Features
Generates up to four processor and six bus clocks,
plus disk, USB and reference clocks
Synchronous clocks skew matched to 250ps window
on PCLKs and 500ps window on BCLKs
TURBO input pin that can speed up the 60 and
66.6 MHz PCLKs by 2.5%.
2.5V or 3.3V output: PCLK (0:3)
3.0V - 5.5V supply range
28-pin SOIC package
Block Diagram
Pin Cnfiguration
28-Pin SOIC
Functionality
TURBO
FS1
FS0
X1, REF
(MHz)
PCLK
(MHz)
1
1
1
1
0
0
0
0
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
14.318
14.318
14.318
14.318
14.318
14.318
14.318
14.318
50
66.8
60
55
83.3
68.4
61.6
75
PCLK(0:3)
VCO/2
BCLK(0:5)
PCLK/2
USB
48 MHz
DISK
24 MHz
All frequencies in MHz, assuming 14.318 MHz input.
Pentium is a trademark of Intel Corporation.
PowerPC is a trademark of Motorola Corporation.
ICS9159C-14RevC062397P
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.
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