Integrated
Circuit
Systems, Inc.
ICS9133X
32 kHz Motherboard Frequency Generator
General Description
The
ICS9133X
is designed to generate clocks for all 286, 386,
486, Pentium and RISC-based motherboards, including lap-
tops and notebook computers. The only external components
required are a 32.768 kHz crystal and decoupling capacitors.
The device generates the 14.318 MHz system clock, eliminating
the need for a 14.318 MHz crystal. High performance applications
may require high speed clock termination components. The
chip includes three independent clock generators plus the
32.768 kHz reference clock to produce all necessary frequencies,
including real time clock/DRAM refresh, master clock, CPU
clock, twice CPUclock frequency, keyboard clock, floppy
disk controller clock, serial communications clock and bus
clocks. Different frequencies from clock #2 can be selected
using the frequency select pins, but clock #1 will be at 14.318
MHz for all standard versions.
Features
•
•
•
•
•
•
•
•
•
•
•
•
•
Single 32.768 kHz crystal generates all PC
motherboard clocks
Cost-reduced version of popular ICS9132
Contains internal crystal load capacitors and
feedback bias
3 independent clock generators
Generates CPU clocks from 12.5 to 100 MHz
Up to 7 output clocks
Separate VDD for 32 kHz clock
Output enable tristates outputs
Power-down options available
Operates from 3.3V or 5.0V supply
Operates up to 66 MHz at 3.3V
Skew controlled 1X and 2X CPU clocks
20-pin PDIP or SOIC package
VDD32 Supply
The
ICS9133X
has a separate power supply for the 32.768
kHz oscillator circuitry. This allows the 32 kHz clock to run
from a battery or other source while the main power to the
chip is disconnected. The VDD32 supply is guaranteed to
operate down to +2.0V, with the clock consuming less than
10µA at +3.3V with the main VDD at 0V.
The frequencies and power-down options in the
ICS9133X
are mask programmable. Customer specific masks can be
made and prototypes delivered within 6-8 weeks from receipt
of order. Integrated Circuit Systems also offers standard versions,
such as that described in this data sheet.
Applications
Notebook/Palmtop Computers: The
ICS9133X
works with
+3V and +5V and a single 32.768 kHz crystal, making it the
ideal solution for generating clocks in portables with minimum
board space. The user can save power by using this single part
instead of oscillators or other frequency generators. The
ICS9133X
further reduces the current consumption by having
the ability to completely shut down the individual clocks
when not in use, while still maintaining the separately powered
32.768 kHz clock.
Block Diagram
9133X Rev A 052897P
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.
ICS9133X
Pin Configuration
Decoding Table for CPU Clock
SCLK22
0
0
0
0
1
1
1
1
SCLK21
0
0
1
1
0
0
1
1
SCLK20
0
1
0
1
0
1
0
1
2XCPU
8
16
32
40
50
66.6
80*
100*
CPU
4
8
16
20
25
33.3
40*
50*
* Only at 5V supply voltage
20-Pin PDIP or SOIC
Pin Descriptions
PIN
NUMBER
PIN NAME
TYPE
DESCRIPTION
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
32 kHz
X2
X1
VDD32
VDD
GND
16 MHz
24 MHz
12 MHz
GND
OE
VDD
14.318 MHz
GND
VDD
2XCPU
CPU
SCLK2
SCLK1
SCLK0
Output
Output
Input
-
-
-
Output
Output
Output
-
Input
-
Output
-
-
Output
Output
Input
Input
Input
32.768 kHz buffered output, powered by VDD32.
Connect 32.768 kHz crystal. Includes internal XTAL load capacitance.
Connect 32.768 kHz crystal. This pin includes internal XTAL load capacitance and
feedback bias for a 32.768 kHz crystal.
Power supply for 32 kHz oscillator only.
Power supply (+3.3 to +5.0V).
GROUND.
16 MHz clock output.
24 MHz clock output.
12 MHz clock output.
GROUND.
OE tristate outputs when low. Has internal pull-up.
Power supply (+3.3 to +5.0V).
14.318 MHz clock output.
GROUND.
Power supply (+3.3 to +5.0V).
2XCPU clock output (see decoding table).
CPU clock output (see decoding table).
CPU clock frequency SELECT2. Has internal pull-up.
CPU clock frequency SELECT1. Has internal pull-up.
CPU clock frequency SELECT0. Has internal pull-up.
2
ICS9133X
Absolute Maximum Ratings
VDD referenced to GND ....................................................................................................................................................... 7V
Operating temperature under bias ....................................................................................................................... 0°C to +70°C
Storage temperature ......................................................................................................................................... -40°C to +150°C
Voltage on I/O pins referenced to GND ........................................................................................ GND -0.5V to VDD +0.5V
Power dissipation .......................................................................................................................................................... 0.5 Watts
Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating
only and functional operation of the device at these or any other conditions above those indicated in the operational sections of
the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect product
reliability.
Electrical Characteristics at 3.3V
Operating V
DD
= +3.0V to 3.7V; T
A
=0°C to 70°C unless otherwise stated
DC Characteristics
PARAMETER
Input Low Voltage
Input High Voltage
Input Low Current
Input High Current
Output Low Voltage
1
Output High Voltage
1
Output High Current
1
Output High Current
1
Output Frequency Change
over Supply and
Temperature
1
Short Circuit Current
1
Supply Current
V
DD
32 Supply Current
V
DD
32 Supply Voltage
Pull-up Resistor Value
Input Clock Rise Time
Input Clock Fall Time
1
Output Rise Time
1
Rise Time
1
Output Fall Time
1
Fall Time
1
Duty Cycle
1
Duty Cycle, reference
clocks
1
Jitter, One Sigma
1
Jitter, Absolute
1
Input Frequency
1
Clock Skew between any
Clock #2 outputs
1
Power-up Time
1
1
SYMBOL
V
IL
V
IH
I
IL
I
IH
V
OL
V
OH
V
OH
V
OH
F
D
TEST CONDITIONS
V
IN
=0V (Pull-up)
V
IN
=V
DD
I
OL
=4mA
I
OH
=-1mA
I
OH
=-4mA
I
OH
=-8mA
With respect to typical
frequency
1
Each output clock
No load, 40 MHz
No load, V
DD
32=3.7V
V
DD
=0 to 3.7V, 32 kHz output
operating
AC Characteristics
MIN
-
0.7V
DD
-12
-2
-
V
DD
-.1V
-
2.4
-
TYP
-
-
-
-
-
-
-
-
.005
MAX
0.2V
DD
-
-
2
0.1
-
-
-
0.05
UNITS
V
V
µA
µA
V
V
V
V
%
I
SC
I
DD
I
DD
32
V
DD
32
Rpu
t
ICr
t
ICf
t
r
t
f
t
f
t
f
d
t
d
t
-
-
-
2.0
-
-
-
-
-
-
-
43/57
40/60
-
-
25
-
-
15
10
5
-
620
-
-
1.5
2.5
1.5
2.5
48/52
43/57
1
2
32.768
100
1,000
-
-
12
-
-
5
5
2
4
2
4
57/43
60/40
3
5
40
500
-
mA
mA
µA
V
k½
µs
µs
ns
ns
ns
ns
%
%
%
%
kHz
ps
ms
15pF
15pF
15pF
15pF
15pF
15pF
load, 0.8 to 2.0V
load, 20% to 80% V
DD
load, 2.0 to 0.8V
load, 80% to 20% V
DD
load @ V
th
=1.4V
load @ 1.4V
2
As compared with clock period.
t
jab
f
i
T
sk
t
pu
From off to 40 MHz
Note: 1. Parameter is guaranteed by design and characterization. Not 100% tested in production.
2. 32 kHz output duty cycle is dependent on crystal used.
4
Embedded System
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