ICS ICS9158-04

Integrated
Circuit
Systems, Inc.
ICS9158-04
Frequency Generator and Integrated Buffer
General Description
Features
The ICS9158-04 is a low cost frequency generator designed
specifically for desktop and notebook PC applications. Up to
six copies of the CPU clock are available, and five or six
copies of the BUS clock are available depending on the status
of the frequency select pins, which eliminates the need for an
external buffer.
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Each high drive (25mA) output is capable of driving a 30pF
load and has a typical duty cycle of 50/50. The clock outputs
are skew controlled to within ±250ps.
The ICS9158-04 makes a gradual transition between
frequencies, so that it meets the Intel cycle-to-cycle timing
specification for 486 and Pentium™ systems.
11 skew-free, high drive CPU/BUS clocks
Up to 66 MHz at 3.3V
±250ps skew between all outputs
Outputs can drive up to 30pF load and 25mA
50±10% duty cycle
Compatible with 486 and Pentium CPUs
Selectable 5/6 or 6/5 CPU/BUS output ratio
On-chip loop filter components
3.0V - 5.5V supply range
24-pin SOIC package
Applications
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Ideal for RISC or CISC systems such as 486, Pentium,
PowerPC,™ etc., requiring multiple CPU and BUS
clocks.
Block Diagram
Pentium is a trademark of Intel Corporation.
PowerPC is a trademark of Motorola Corporation.
NOTE: THIS DATA SHEET, ICS9158-04, IS AN ADDENDUM TO THE EXISTING
ICS9158 DATA SHEET. ALL INFORMATION IN THIS DATA SHEET SUPERSEDES THE
DATA FOUND IN THE ORIGINAL ICS9158 DATA SHEET.
9158-04 RevC 8/10/98
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.
ICS9158-04
Pin Configuration
24-Pin SOIC
Pin Description
PIN NUMBER
PIN NAME
TYPE
1
CLK1A
OUT
2
X2
OUT
DESCRIPTION
CPU clock output.
Crystal connection output, which includes output crystal load capacitance.
Crystal connection input, which includes crystal load capacitance and
feedback bias for a nominal 14.31818 MHz parallel-resonance 12pF crystal.
3
X1
IN
4
VDD
PWR
5
GND
PWR
Digital GROUND.
6
CLK1B
OUT
CPU clock output.
Digital POWER SUPPLY.
7
CLK1C
OUT
CPU clock output.
8
CLK1D
OUT
CPU clock output.
9
AGND
PWR
10
OE
IN
ANALOG GROUND.
11
CLK2E
OUT
2X CPU clock output.
12
GND
PWR
Digital GROUND.
OUTPUT ENABLE. Tristates all outputs when low.*
13
CLK12
OUT
CPU clock output.
14
CLK1E
OUT
CPU clock output.
CPU clock frequency select 2.*
15
FS2
OUT
16
AVDD
PWR
ANALOG power supply.
17
CLK2D
OUT
2X CPU clock output.
18
CLK2C
OUT
2X CPU clock output.
19
GND
PWR
Digital GROUND.
20
VDD
PWR
Digital POWER SUPPLY.
21
CLK2B
OUT
2X CPU clock output.
22
CLK2A
OUT
23
FS1
IN
CPU clock frequency select #1.*
24
FS0
IN
CPU clock frequency select #0.*
2X CPU clock output.
* Input pin has internal pull-up to VDD.
2
ICS9158-01
Functionality
VDD=5V±10% or 3.3V±10%, TEMP=0-70°C
OE
FS2
FS1
FS0
1
1
1
1
1
1
1
1
0
0
0
0
0
1
1
1
1
X
0
0
1
1
0
0
1
1
X
0
1
0
1
0
1
0
1
X
CLK2
(MHz)
14/6 x X1
14/4 x X1
14/3 x X1
42/10 x X1
14/6 x X1
14/4 x X1
14/3 x X1
42/10 x X1
--
X1, X2
(MHz)
14.318
14.318
14.318
14.318
14.318
14.318
14.318
14.318
14.318
3
CLK2(A:E)
(MHz)
33.3
50
66.6
60
33.3
50
66.6
60
Tristate
CLK1(A:E)
(MHz)
16.6
25
33.3
30
16.6
25
33.3
30
Tristate
CLK12
(MHz)
33.3
50
66.6
60
16.6
25
33.3
30
Tristate
ICS9158-04
LEAD COUNT
DIMENSION L
24L
0.604
24 Lead SOIC
Ordering Information
ICS9158-04M
Example:
ICS XXXX-PPP M
Package Type
M=SOIC
Pattern Number (2 or 3 digit number for parts with ROM code patterns)
Device Type (consists of 3 or 4 digit numbers)
Prefix
ICS, AV=Standard Device; GSP=Genlock Device
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