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Description
The MK3230 is the smallest size, lowest power system
clock synthesizer available. It is the ideal way to
generate clocks for portable computers, PDAs, and
other devices where low power is required. Using
analog Phase-Locked Loop (PLL) techniques, the
device operates from a single 32.768 kHz crystal to
produce the 32.768kHz, CPU, system, keyboard
controller, and floppy (or super I/O) controller output
clocks.
The device has two power down modes. From the CPU
decoding table (when FS0, FS1, and FS2 all are low),
the CPU and 14.3 MHz system clocks can be turned
off. Also, the keyboard and 24 MHz peripheral clocks
can be shut off from PD24+KBD (pin 10). The part has
a separate VDD32 pin for the 32 kHz clock, allowing
it to run at a different voltage (down to 2.0V) from the
rest of the chip, allowing it to run from a back-up
battery.
MK3230
Portable System Clock Synthesizer
Features
• Packaged in 16 pin narrow (0.150”) SOIC
• Input crystal frequency of 32.768 kHz
• Lowest power solution available
• Lowest profile clock solution where height is critical
• Output clock frequencies up to 80 MHz
• Five output clocks
• 3.3V or 5.0V operation
• Duty cycle of 45/55
• Seven selectable CPU frequencies
• CPU and peripheral clock power downs
• Separate battery supply pin for 32 kHz
• IDD less than 5µA when 32 kHz running
• Available with either 12MHz (-01) or 16MHz (-02)
keyboard clock output
• 14.3MHz output is not suitable for driving PLL for
CRT. Will drive all other functions
• 32kHz crystals require long startup (>500ms)
Block Diagram
VDD
GND
CPUS0
CPUS1
CPUS2
Clock Synthesis
and Control
Circuitry
Output
Buffer
Output
Buffer
Output
Buffer
Output
Buffer
CPUCLK
12 or 16 MHz
PD24+KBD
24.00 MHz
14.32 MHz
VDD32
X1
Crystal
Oscillator
X2
Output
Buffer
32.768 kHz
32.768 kHz
crystal
MDS 3230 F
1
Revision 022798
Printed 11/16/00
Integrated Circuit Systems, Inc.•525 Race Street•San Jose•CA•95126•(408)295-9800tel•www.icst.com
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Pin Assignment
CPUS2
X2
X1
VDD32
VDD
GND
24M
32K
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
CPUS1
CPUS0
CPUCLK
VDD
GND
14.3M
PD24+KBD
KBOUT
MK3230
Portable System Clock Synthesizer
CPU Clock Decoding
CPUS2 CPUS1 CPUS0 CPUCLK (MHz)
0
0
0
Off+14M off
0
0
1
80.00
0
1
0
25.00
0
1
1
66.66
1
0
0
20.00
1
0
1
50.00
1
1
0
33.33
1
1
1
4.00
Frequency transitions (except going to/from
off) will occur smoothly, and are compatible
with all 486 processors.
Pin Descriptions
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Name
CPUS2
X2
X1
VDD32
VDD
GND
24M
32K
KBOUT
PD24+KBD
14.3M
GND
VDD
CPUCLK
CPUS0
CPUS1
Type
I
O
I
P
P
P
O
O
O
I
O
P
P
O
I
I
Description
Select 2 for CPUCLK frequencies. See Table above.
Crystal connection. Connect to 32.768 kHz crystal.
Crystal connection. Connect to 32.768 kHz crystal.
Separate power supply connection for 32.768kHz clock. Will operate to 2.0V.
Connect to +3.3V or +5V. Must be the same voltage as pin 13.
Connect to ground.
24 MHz floppy (or super I/O) clock output.
32.768 kHz square wave clock output.
Keyboard clock output. Either 12MHz (-01) or 16MHz (-02)
Power Down 24M+keyboard. Shuts off both clock outputs (pins 7,9) when low.
14.318 MHz system clock output. Do not drive a CRT PLL device with this output.
Connect to ground.
Connect to +3.3V or +5V. Must be the same voltage as pin 5.
CPUCLK output. See Table above.
Select 0 for CPUCLK frequencies. See Table above.
Select 1 for CPUCLK frequencies. See Table above.
Type: I = Input, O = output, P = power supply connection
Power Down status:
Output clocks will stop in a low state when powered down
External Components
The MK3230 requires a minimum number of external components for proper operation. Decoupling
capacitors of 0.1µF should be connected between VDD and GND, and VDD32 and GND, as close to the
MK3230 as possible. A 10kΩ series resistor should be used to filter the VDD32 pin. A series termination
resistor of 33Ω may be used for each clock output. The device does not require (nor do we recommend)
capacitors connected to the crystal pins. The 32.768 kHz crystal must be connected as close to the chip as
possible. See Application Brief MAB02 for a discussion on tuning for use on a real time clock (RTC).
MDS 3230 F
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Revision 022798
Printed 11/16/00
Integrated Circuit Systems, Inc.•525 Race Street•San Jose•CA•95126•(408)295-9800tel•www.icst.com
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Electrical Specifications
Parameter
Supply Voltage, VDD
Inputs and Clock Outputs
Ambient Operating Temperature
Soldering Temperature
Storage Temperature
Conditions
MK3230
Portable System Clock Synthesizer
Minimum
Typical
Maximum
7
VDD+0.5
70
260
150
5.5
5.5
0.8
2.4
0.4
1.9
0.4
2.4
0.4
25
3.5
15
2.5
±30
±100
7
15
Units
V
V
°C
°C
°C
V
V
V
V
V
V
V
V
V
V
mA
µA
mA
µA
mA
mA
pF
pF
ABSOLUTE MAXIMUM RATINGS (note 1)
Referenced to GND
Referenced to GND
Max of 30 seconds
-65
3.0
2.0
2.0
-0.5
0
DC CHARACTERISTICS
Operating Voltage, VDD
Operating Voltage,VDD32
Input High Voltage, VIH
Input Low Voltage, VIL
Output High Voltage, VOH
Output Low Voltage, VOL
Input High Voltage, VIH
Input Low Voltage, VIL
Output High Voltage, VOH
Output Low Voltage, VOL
IDD Operating Supply Current, 5V
IDD32 with only 32 kHz running, 5V
IDD Operating Supply Current, 3.3V
IDD32 with only 32 kHz running, 3.3V
Short Circuit Current, 5V
Short Circuit Current, 5V
Input Capacitance
Internal Crystal Capacitance
VDD=5V
VDD=5V
VDD=5V, IOH=-25mA
VDD=5V, IOL=25mA
VDD=3.3V
VDD=3.3V
VDD=3.3V, IOH=-8mA
VDD=3.3V, IOL=8mA
No Load, 80MHz
No Load
No Load, 80MHz
No Load
32 kHz output
Each MHz output
Pins 2, 3 only
AC CHARACTERISTICS
Input Frequency
32.768
kHz
Output Clock Rise and Fall Time, 0.2 to 0.8VDD
2
ns
Output Clock Duty Cycle, all MHz clocks
At VDD/2
45
49 to 51
55
%
32.768 kHz Clock Duty Cycle
At VDD32/2
57
%
Absolute Clock Period Jitter, CPU clock
25 to 80 MHz
-500
500
ps
Power up time, CPU off to 80 MHz, 32k running VDD=3.3 or 5V
9
ms
Transition time, 4 MHz to 80 MHz
VDD=3.3 or 5V
4
ms
Transition time, 80 MHz to 4 MHz
VDD=3.3 or 5V
2.5
ms
Power on time,VDD32=0V to all clocks stable
32.768kHz crystal with ESR
≤25kΩ
500
750
ms
Note 1: Stresses beyond those listed under Absolute Maximum Ratings could cause permanent damage to the device. Prolonged
exposure to levels above the operating limits but below the Absolute Maximums may affect device reliability.
Note on the 14.32 MHz output
: The actual output frequency from this clock is 14.3196 MHz, versus
14.31818 MHz that has been traditional. This output can be used as the input to digital chips providing
functions such as timing or keyboard, but it should NOT be used to drive a graphics PLL that is used for a
CRT display. Instead, use a 14.318MHz crystal as the input to the CRT graphics device.
MDS 3230 F
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Revision 022798
Printed 11/16/00
Integrated Circuit Systems, Inc.•525 Race Street•San Jose•CA•95126•(408)295-9800tel•www.icst.com
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Input and Output Voltages
MK3230
Portable System Clock Synthesizer
The MK3230 can operate with VDD = 3.0V to 5.5V, and VDD32 = 2.0V to 5.5V in any combination.
Both VDD pins (pin #5 and pin #13) must be connected to the same voltage.
The amplitude of the 32.768 kHz output clock will be equal to VDD32, and the amplitude of the MHz
clocks will be equal to VDD.
If using a clock input, the input voltage applied to X1 may not exceed VDD32, and the amplitude of any
other input may not exceed VDD. Consult MicroClock if your application is an exception to this.
Package Outline and Package Dimensions
16 pin SOIC narrow
Symbol
A
b
c
D
E
H
e
h
Q
Inches
Min
Max
0.055 0.070
0.013 0.019
0.007 0.010
0.385 0.400
0.150 0.160
0.225 0.245
.050 BSC
0.016
0.004
0.01
Millimeters
Min
Max
1.397
1.778
0.330
0.483
0.191
0.254
9.779 10.160
3.810
4.064
5.715
6.223
1.27 BSC
0.406
0.102
0.254
E
H
D
Q
e
Ordering Information
Part/Order Number
MK3230-01S
MK3230-02S
MK3230-01STR
MK3230-02STR
h x 45°
A
c
b
Marking
MK3230-01S
MK3230-02S
MK3230-01S
MK3230-02S
Keyboard frequency
12 MHz
16 MHz
12 MHz
16 MHz
Package
16 pin SOIC
16 pin SOIC
Add Tape & Reel
Add Tape & Reel
Temperature
0-70°C
0-70°C
0-70°C
0-70°C
While the information presented herein has been checked for both accuracy and reliability, MicroClock Incorporated assumes no responsibility for either its use or for the
infringement of any patents or other rights of third parties, which would result from its use. No other circuits, patents, or licenses are implied. This product is intended for use in
normal commercial applications. Any other applications such as those requiring extended temperature range, high reliability, or other extraordinary environmental requirements
are not recommended without additional processing by MicroClock. MicroClock reserves the right to change any circuitry or specifications without notice. MicroClock does not
authorize or warrant any MicroClock product for use in life support devices or critical medical instruments.
MDS 3230 F
4
Revision 022798
Printed 11/16/00
Integrated Circuit Systems, Inc.•525 Race Street•San Jose•CA•95126•(408)295-9800tel•www.icst.com
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