ICS MK1491

MK1491-06
AMD Geode™ Clock Source
Description
Features
The MK1491-06 is a low-cost, low-jitter,
high-performance clock synthesizer for AMD’s
Geode-based computer and portable appliance
applications. Using patented analog Phased-Locked
Loop (PLL) techniques, the device accepts a 14.318
MHz crystal input to produce multiple output clocks. It
provides selectable PCI local bus and AC97 audio
clocks, 24 MHz and 48 MHz clocks for Super I/O and
USB, as well as multiple Reference outputs.
• Packaged in 28-pin SOIC or in 28-pin SSOP
• Available in Pb (lead) free
• Provides all critical timing for the AMD Geode
companion chip
•
•
•
•
•
•
•
•
The device has multiple power-down modes to reduce
power consumption.
Four PCI clocks
Selectable PCIF on up to 2 outputs
Early PCI clock selectability
Up to 4 Reference clocks
48 MHz USB and 24MHz SIO support
AC97 audio clock
Multiple power down modes
Low EMI Enable pin reduces EMI radiation on PCI
clocks (patented)
• Operating voltage of 3.3 V ±5%
Block Diagram
VDD
GND
6
5
2
PCI Frequency Select
Low EMI Enable
PCIF Function Enable
3
Early PCI Enable
PCI
Clocks
SLOW#
PCI
EPCI/PCI
PCISTP#
PWRDWN#
Audio Select
16.394 MHz or
24.576 MHz or
49.152 MHz
Audio
Clock
48 MHz
Fixed
Clocks
14.3M/24M Select
XI
14.31818 MHz
crystal
14.318 MHz or
24 MHz
MUX
Crystal
Oscillator
3
14.318 MHz
XO
1
MDS 1491-06 J
Integrated Circuit Systems, Inc.
●
525 Race Street, San Jose, CA 95126
Revision 110204
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MK1491-06
AMD Geode™ Clock Source
Pin Assignment
PCI Frequency Select Table
VDD
1
28
AC97 AUDIO (PEN)
XI
2
27
PCI
XO
3
26
VDD
TS
FS
PCI
0
0
Tristate all clocks
0
1
Reserved
0
30 MHz
GND
4
25
PCI
M
14.3M (TS)
5
24
PCI
M
1
33.3 MHz
14.3M
6
23
GND
1
0
25 MHz
GND
7
22
PCI (EPCI#)
1
1
37.5 MHz
14.3M (SEL AUDIO)
8
21
48M (LE#)
VDD
9
20
VDD
SLOW#
10
19
24M/14.3M
GND
11
18
VDD
24M/14.3M Frequency Select Table
SEL24
FS
12
17
GND
0
SEL24
13
16
PCISTP#
1
VDD
14
15
PWRDWN#
24M/14.3M
14.31818 MHz
24.0 MHz
PCIF Enable Control
PEN
Early PCI Control Table
EPCI#
PCI (Pin 22)
0
1 ns early
1
Normal
ON
1
OFF
0
PCI
PCI
M
PCI
PCIF
1
PCIF
PCIF
AC97 Audio Frequency Select
PCI Low EMI
0
Pin 24
PCIF continues to run in PCI STOP mode. See table on page
4.
EMI Control
LE#
Pin 25
SEL AUDIO
Spread direction is DOWN.
AC97 AUDIO
0
16.9344 MHz
M
24.576 MHz
1
49.152 MHz
Pin Descriptions
Pin
Number
Pin
Name
Pin
Type
1, 9, 14
VDD
P
Connect to +3.3 V. Must be same voltage on all pins.
2
XI
I
Crystal connection. Connect to a 14.31818 MHz crystal or input clock.
3
XO
O
Crystal connection. Connect to a 14.31818 MHz crystal, or leave
unconnected for clock.
4, 7, 11,
17, 23
GND
P
Connect to Ground.
5
14.3M (TS)
TI/O
6
14.3M
O
14.318 MHz output. Input control for all clocks per table above.
14.318 MHz buffered reference clock output.
2
MDS 1491-06 J
Integrated Circuit Systems, Inc.
Pin Description
●
525 Race Street, San Jose, CA 95126
Revision 110204
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MK1491-06
AMD Geode™ Clock Source
Pin
Number
Pin
Name
Pin
Type
Pin Description
8
14.3M (SEL
AUDIO)
TI/O
10
SLOW#
I
PCI normal or slow mode select input per table on page 4.
12
FS
I
Frequency Select for PCI clocks per table above.
13
SEL24
I
Fixed frequency select input per table above. Selects frequency on pin
19.
15
PWRDWN#
I
Power down control; defined in table on page 4.
16
PCISTP#
I
PCI Stop power down control; defined in table on page 4.
18, 20, 26
VDD
P
Connect to +3.3 V. Must be same voltage on all pins.
19
24M/14.3M
O
Fixed frequency clock output per table above.
21
48 (LE#)
I/O
Fixed frequency clock output and low EMI (spread spectrum) enable
input per table above.
22
PCI (EPCI#)
I/O
PCI Output clock that can be early. Input control for Early PCI per table
above.
24
PCI
O
PCI Output clock. PCI/PCIF control set by PEN per table above.
25
PCI
O
PCI Output clock. PCI/PCIF control set by PEN per table above.
27
PCI
O
PCI Output clock.
28
AC97 AUDIO
(PEN)
TI/O
14.318 MHz output and audio frequency select input per table above.
Audio clock output and PCIF Function Enable per table above.
KEY:
I = Input
TI = Tri-level
O = Output
P = Power supply connection
(T)I/O = Input on power up, becomes an Output after 10 ms
Weak internal pull-up resistors are present on SEL24, EPCI#, FS, LE#, PCISTP#, and SLOW#. These pins
should be tied to VDD or GND, and not be left floating. Internal resistors on PEN, SEL AUDIO, and TS pull
to mid-level (M).
3
MDS 1491-06 J
Integrated Circuit Systems, Inc.
●
525 Race Street, San Jose, CA 95126
Revision 110204
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MK1491-06
AMD Geode™ Clock Source
Power Down Control Table
PCISTP# PWRDWN# SLOW#
MODE
PCI
PCIF
24/14.3
14.3
Description
X
0
X
Power down
LOW
LOW
LOW
LOW
All outputs low. PLL’s
and oscillators off.
0
1
X
PCI STOP
LOW
ON
ON
ON
PCI clocks
synchronously enter
and leave low state.
1
1
X
ON
ON
ON
ON
ON
All clocks on.
Key: 1 = connected to VDD, 0 = connected to ground, X = any valid logic level, combination inputs/outputs
should be connected to VDD or ground through a 10 kΩ resistor as shown below.
Power-on Default Conditions
Pin #
Function
Default
5
TS
M
All outputs enabled.
8
SEL AUDIO
M
Audio clock (pin 28) set to 24.576 MHz
10
SLOW#
1
PCI clocks set to 33.3 MHz. Refer to Power Down Control Table above.
12
FS
1
PCI frequency = 33.3 MHz.
13
SEL 24
1
24M/14.3M (pin 19) set to 24 MHz.
15
PWRDWN#
1
All clocks running.
16
PCISTP#
1
PCI clocks running.
21
LE#
1
Low EMI function OFF
22
EPCI#
1
Pin 22 set to normal PCI signal (not early).
28
PEN
M
PCI (pin 25) set to PCI clock (33.33 MHz). PCI (pin 24) set to PCIF clock
(33.33 MHz).
4
MDS 1491-06 J
Integrated Circuit Systems, Inc.
Condition
●
525 Race Street, San Jose, CA 95126
Revision 110204
●
tel (408) 297-1201
●
www.icst.com
MK1491-06
AMD Geode™ Clock Source
External Components
The MK1491-06 requires some inexpensive external
components for proper operation. Decoupling
capacitors of 0.1µF should be connected on each VDD
pin to ground, as close to the MK1491-06 as possible.
A series termination resistor of 33Ω may be used for
each clock output. See the discussion below for other
external resistors required for proper I/O operation. The
14.3 MHz oscillator has internal caps that provide the
proper load for a parallel resonant crystal with CL=18
pF. For tuning with other values of CL, the formula
2*(CL-18) gives the value of each capacitor that should
be connected between X1 and ground and X2 and
ground.
I/O Structure
The MK1491-06 provides more functionality in a 28-pin
package by using a unique I/O technique. The device
checks the status of all I/O pins during power-up and at
exit from the Power Down state. This status (pulled
high, low, or mid-level) then determines the frequency
selections and power down modes (see the tables on
pages 2 and 4). Within 10ms after power up, the inputs
change to outputs and the clocks start up. In the
diagrams to the right, the 33Ω resistors are the normal
output termination resistors. The 10kΩ resistor pulls
low to generate a logic zero. Weak internal pull-up
resistors are present on SEL24, EPCI#, FS, LE#,
PCISTP#, and SLOW#. These pins should be
connected directly to VDD or GND if not under active
control. Internal resistors on PEN, SEL AUDIO, and TS
pull to a mid-level (M).
33
For select
= 0 (low)
To load*
I/O
10 k
Do not stuff for
“1” selection
*Note: Do not use a TTL load. This will overcome the
10 kΩ pull-down and force the input to a logic 1.
5
MDS 1491-06 J
Integrated Circuit Systems, Inc.
●
525 Race Street, San Jose, CA 95126
Revision 110204
●
tel (408) 297-1201
●
www.icst.com
MK1491-06
AMD Geode™ Clock Source
Absolute Maximum Ratings
Stresses above the ratings listed below can cause permanent damage to the MK1491-06. These ratings,
which are standard values for ICS commercially rated parts, are stress ratings only. 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 can
affect product reliability. Electrical parameters are guaranteed only over the recommended operating
temperature range.
Item
Rating
Supply Voltage, VDD
7V
All Inputs and Outputs
-0.5 V to VDD+0.5 V
Ambient Operating Temperature
0 to +70°C
Storage Temperature
-65 to +150°C
Junction Temperature
125°C
Soldering Temperature
260°C
Recommended Operation Conditions
Parameter
Min.
Ambient Operating Temperature
Typ.
0
Power Supply Voltage (measured in respect to GND)
+3.15
+3.3
Max.
Units
+70
°C
+3.45
V
DC Electrical Characteristics
Unless stated otherwise, VDD = 3.3 V ±5%, Ambient Temperature 0 to +70°C
Parameter
Symbol
Conditions
Min.
Typ.
Max.
Units
3.3
3.45
V
Operating Voltage
VDD
3.15
Input High Voltage
VIH
2
Input Mid-level Voltage
VIM
1.2
Input Low Voltage
VIL
Output High Voltage
VOH
IOH = -8 mA
Output Low Voltage
VOL
IOL = 8 mA
Output High Voltage
VOH
IOH = -8 mA
Operating Supply Current
IDD
33 MHz, no load
Integrated Circuit Systems, Inc.
525 Race Street, San Jose, CA 95126
0.8
V
V
V
30
mA
15
µA
±60
mA
7
pF
6
●
V
V
VDD-0.4
CIN
MDS 1491-06 J
1.6
0.4
VDD = 3.3 V
Input Capacitance
1.4
2.4
Power Down Mode Supply
Current
Short Circuit Current,
SIngle Output Driver
V
Revision 110204
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MK1491-06
AMD Geode™ Clock Source
AC Electrical Characteristics
Unless stated otherwise, VDD = 3.3 V ±5%, Ambient Temperature 0 to +70° C
Parameter
Symbol
Conditions
Min.
Typ.
Max.
14.31818
Units
Input Frequency
FIN
Output Clock Rise Time
tOR
20% to 80%
1.5
ns
Output Clock Fall Time
tOF
80% to 20%
1.5
ns
Output Clock Duty Cycle, all
MHz Clocks
tOD
At 1.5 V
55
%
500
ps
PCI Output to Output Skew
45
MHz
49 to 51
Rising edges at 1.5 V
Skew of EPCI with respect to
PCI
Cycle-to-Cycle Jitter, PCI clocks
EMI Reduction, peaks of 5th 19th odd harmonics
33.3 MHz PCI Clock
1
ns
250
ps
6
11
dB
Power-up Time, PWRDWN#
High to all Clocks Stable
8
20
ms
Power-on Time, applied VDD to
all Clocks Stable
12
25
ms
Thermal Characteristics
Parameter
Symbol
Thermal Resistance Junction to
Ambient
Thermal Resistance Junction to Case
Min.
Typ.
Max. Units
θJA
Still air
100
°C/W
θJA
1 m/s air flow
80
°C/W
θJA
3 m/s air flow
67
°C/W
60
°C/W
θJC
7
MDS 1491-06 J
Integrated Circuit Systems, Inc.
Conditions
●
525 Race Street, San Jose, CA 95126
Revision 110204
●
tel (408) 297-1201
●
www.icst.com
MK1491-06
AMD Geode™ Clock Source
Marking Diagram
28
ICS
15
######
YYWW
MK1491-06R
1
14
Notes:
1. ###### is the lot code.
2. YYWW is the last two digits of the year, and the week number that the part was assembled.
8
MDS 1491-06 J
Integrated Circuit Systems, Inc.
●
525 Race Street, San Jose, CA 95126
Revision 110204
●
tel (408) 297-1201
●
www.icst.com
MK1491-06
AMD Geode™ Clock Source
Package Outline and Package Dimensions (28-pin SOIC, 150 mil Body)
Package dimensions are kept current with JEDEC Publication No. 95, MO-153
C
N
Millimeters
L
INDEX
AREA
H
E
h x 45°
1 2
α
D
A
A1
e
Symbol
Min
A
A1
B
C
D
E
e
H
h
L
α
Inches
Max
Min
Max
2.65
0.104
0.10
0.33
0.51
0.18
0.32
17.70
18.40
7.40
7.60
1.27 Basic
10.00
10.65
0.25
0.75
0.40
1.27
0°
8°
.0040
.013
.020
.007
.013
.697
.724
.291
.299
0.050 Basic
.394
.419
.010
.029
.016
.050
0°
8°
SEATING
PLANE
B
.10 (.004)
9
MDS 1491-06 J
Integrated Circuit Systems, Inc.
●
525 Race Street, San Jose, CA 95126
Revision 110204
●
tel (408) 297-1201
●
www.icst.com
MK1491-06
AMD Geode™ Clock Source
Package Outline and Package Dimensions (28-pin SSOP, 150 mil Body, 0.025 mm Pitch)
Package dimensions are kept current with JEDEC Publication No. 95, MO-153
28
Millimeters
Symbol
E1
A
A1
A2
b
C
D
E
E1
e
L
α
aaa
E
INDEX
AREA
1 2
D
A
2
Min
A
Inches
Max
Min
1.35
1.75
0.10
0.25
-1.50
0.20
0.30
0.18
0.25
9.80
10.00
5.80
6.20
3.80
4.00
0.635 Basic
0.40
1.27
0°
8°
-0.10
Max
.053
.069
.0040
.010
-.059
.008
.012
.007
.010
.386
.394
.228
.244
.150
.157
0.025 Basic
.016
.050
0°
8°
-0.004
A
1
c
-Ce
SEATING
PLANE
b
L
aaa C
Ordering Information
Part / Order Number
Marking
Shipping Packaging
Package
Temperature
MK1491-06R
MK1491-06R
Tubes
28-pin SSOP
0 to +70°C
MK1491-06RTR
MK1491-06R
Tape and Reel
28-pin SSOP
0 to +70°C
MK1491-06RLF
MK1491-06RLF
Tubes
28-pin SSOP
0 to +70°C
MK1491-06RLFTR
MK1491-06RLF
Tape and Reel
28-pin SSOP
0 to +70°C
MK1491-06S
MK1491-06S
Tubes
28-pin SOIC
0 to +70°C
MK1491-06STR
MK1491-06S
Tape and Reel
28-pin SOIC
0 to +70°C
MK1491-06SLF
MK1491-06SLF
Tubes
28-pin SOIC
0 to +70°C
MK1491-06SLFTR
MK1491-06SLF
Tape and Reel
28-pin SOIC
0 to +70°C
“LF” denotes Pb (lead) free package.
While the information presented herein has been checked for both accuracy and reliability, Integrated Circuit Systems (ICS)
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 ICS. ICS reserves the right to change any
circuitry or specifications without notice. ICS does not authorize or warrant any ICS product for use in life support devices or
critical medical instruments.
10
MDS 1491-06 J
Integrated Circuit Systems, Inc.
●
525 Race Street, San Jose, CA 95126
Revision 110204
●
tel (408) 297-1201
●
www.icst.com