DATASHEET
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
PCI Frequency Select
VDD
GND
6
5
2
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
IDT™ / ICS™ AMD GEODE™ CLOCK SOURCE
1
MK1491-06
REV J 110204
MK1491-06
AMD GEODE™ CLOCK SOURCE
CLOCK SYNTHESIZER
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
0
1
Pin 24
0
PCI
PCI
M
PCI
PCIF
1
PCIF
PCIF
PCIF continues to run in PCI STOP mode. See table on page 4.
AC97 Audio Frequency Select
EMI Control
LE#
Pin 25
SEL AUDIO
PCI Low EMI
AC97 AUDIO
ON
0
16.9344 MHz
OFF
M
24.576 MHz
1
49.152 MHz
Spread direction is DOWN.
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
IDT™ / ICS™ AMD GEODE™ CLOCK SOURCE
Pin Description
14.318 MHz output. Input control for all clocks per table above.
14.318 MHz buffered reference clock output.
2
MK1491-06
REV J 110204
MK1491-06
AMD GEODE™ CLOCK SOURCE
CLOCK SYNTHESIZER
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).
IDT™ / ICS™ AMD GEODE™ CLOCK SOURCE
3
MK1491-06
REV J 110204
MK1491-06
AMD GEODE™ CLOCK SOURCE
CLOCK SYNTHESIZER
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).
IDT™ / ICS™ AMD GEODE™ CLOCK SOURCE
Condition
4
MK1491-06
REV J 110204
MK1491-06
AMD GEODE™ CLOCK SOURCE
CLOCK SYNTHESIZER
External Components
I/O Structure
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.
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.
IDT™ / ICS™ AMD GEODE™ CLOCK SOURCE
5
MK1491-06
REV J 110204
MK1491-06
AMD GEODE™ CLOCK SOURCE
CLOCK SYNTHESIZER
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
Input Capacitance
IDT™ / ICS™ AMD GEODE™ CLOCK SOURCE
1.4
1.6
V
0.8
V
2.4
V
0.4
VDD-0.4
Power Down Mode Supply
Current
Short Circuit Current,
SIngle Output Driver
V
VDD = 3.3 V
CIN
6
V
V
30
mA
15
µA
±60
mA
7
pF
MK1491-06
REV J 110204
MK1491-06
AMD GEODE™ CLOCK SOURCE
CLOCK SYNTHESIZER
AC Electrical Characteristics
Unless stated otherwise, VDD = 3.3 V ±5%, Ambient Temperature 0 to +70° C
Parameter
Symbol
Conditions
Min.
Typ.
Max.
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
14.31818
Units
45
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
49 to 51
33.3 MHz PCI Clock
MHz
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
Thermal Resistance Junction to
Ambient
Thermal Resistance Junction to Case
IDT™ / ICS™ AMD GEODE™ CLOCK SOURCE
Symbol
Conditions
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
MK1491-06
REV J 110204
MK1491-06
AMD GEODE™ CLOCK SOURCE
CLOCK SYNTHESIZER
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.
3. Bottom marking: country of origin.
IDT™ / ICS™ AMD GEODE™ CLOCK SOURCE
8
MK1491-06
REV J 110204
MK1491-06
AMD GEODE™ CLOCK SOURCE
CLOCK SYNTHESIZER
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
Symbol
A
A1
B
C
D
E
e
H
h
L
α
H
E
h x 45°
1 2
α
D
A
A1
e
B
Min
Max
Inches
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
.10 (.004)
IDT™ / ICS™ AMD GEODE™ CLOCK SOURCE
9
MK1491-06
REV J 110204
MK1491-06
AMD GEODE™ CLOCK SOURCE
CLOCK SYNTHESIZER
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
A
Min
Inches
Max
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
Min
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
b
SEATING
PLANE
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.
IDT™ / ICS™ AMD GEODE™ CLOCK SOURCE
10
MK1491-06
REV J 110204
MK1491-06
AMD GEODE™ CLOCK SOURCE
CLOCK SYNTHESIZER
Innovate with IDT and accelerate your future networks. Contact:
www.IDT.com
For Sales
For Tech Support
800-345-7015
408-284-8200
Fax: 408-284-2775
Corporate Headquarters
Asia Pacific and Japan
Europe
Integrated Device Technology, Inc.
6024 Silver Creek Valley Road
San Jose, CA 95138
United States
800 345 7015
+408 284 8200 (outside U.S.)
Integrated Device Technology
Singapore (1997) Pte. Ltd.
Reg. No. 199707558G
435 Orchard Road
#20-03 Wisma Atria
Singapore 238877
+65 6 887 5505
IDT Europe, Limited
Prime House
Barnett Wood Lane
Leatherhead, Surrey
United Kingdom KT22 7DE
+44 1372 363 339
© 2006 Integrated Device Technology, Inc. All rights reserved. Product specifications subject to change without notice. IDT and the IDT logo are trademarks of Integrated Device
Technology, Inc. Accelerated Thinking is a service mark of Integrated Device Technology, Inc. All other brands, product names and marks are or may be trademarks or registered
trademarks used to identify products or services of their respective owners.
Printed in USA