MK2011
Fast Ethernet Clock Source
MDS 2011 B
1
Revision 120597
Printed 11/15/00
MicroClock Division of ICS1271
Parkmoor Ave.San JoseCA95126(408)295-9800tel(408)295-9818fax
I C R O
C
LOC K
The MK2011 is the ideal way to generate clocks
for Fast Ethernet cards or systems. It provides
20MHz, 25MHz, and 50MHz clocks. In an 8 pin
SOIC, the MK2011 can save component count,
board space, and cost over surface mount crystals
and oscillators, and increase reliability by
eliminating two or three mechanical devices from
the board.
MicroClock offers many other clocks for
computers and computer peripherals. Consult
MicroClock when you need to remove crystals and
oscillators from your board.
Block Diagram
Description
Features
Packaged in 8 pin SOIC
Input crystal or clock frequency of 20.00 MHz
Lowest jitter in the industry reliably clocks
sensitive Ethernet devices.
Output clock frequencies of 20.00 MHz,
25.00 MHz, and 50.00 MHz
25mA drive capability at TTL levels
3.3V or 5V10% supply voltage
Advanced, low power CMOS process
Insensitive to input clock duty cycle
Crystal
Oscillator
VDD GND
PLL
Clock Synthesis
Circuitry
Output
Buffer
Output
Buffer
50 MHz
20 MHz
X1
X2
20.00 MHz
xtal or clock
Output
Buffer
25 MHz
MK2011
Fast Ethernet Clock Source
MDS 2011 B
2
Revision 120597
Printed 11/15/00
MicroClock Division of ICS1271
Parkmoor Ave.San JoseCA95126(408)295-9800tel(408)295-9818fax
I C R O
C
LOC K
Number
Name
Type
Description
1
X1/ICLK
I
Crystal Connection. Connect to a 20.000 MHz crystal or clock.
2
VDD
P
Connect to +5V.
3
GND
P
Connect to ground.
4
25M
O
25.000 MHz clock output.
5
50M
O
50.000 MHz clock output.
6
GND
P
Connect to ground.
7
20M
O
20.000 MHz buffered crystal clock output.
8
X2
O
Crystal Connection to a 20.000 MHz crystal, or leave unconnected for clock input.
Pin Descriptions
Key: I = Input, O = output, P = power supply connection
Pin Assignment
20.00 MHz in
(crystal caps not
shown)
Pin 1
33
(optional)
2
3
5
6
7
0.1F
25MHz out
50MHz out
G
V
33
(optional)
Suggested Layout
4
8
External Components/Crystal Selection
A minimum number
of external components are required for proper oscillation. For a crystal input, one
22pF load capacitor should be connected to each of the X1 and X2 pins and ground, and a parallel
resonant 20.000 MHz, 16pF load, crystal is recommended. The frequency tolerance of the crystal should
be 50ppm or better. For a clock input, connect to X1 and leave X2 unconnected. A decoupling capacitor of
0.1F should be connected between VDD and GND on pins 2 and 3, and 33
terminating resistors
should be used on clock outputs with traces longer than 1 inch.
33
(optional)
20MHz
out
1
8
2
3
4
7
6
5
X1/ICLK
20M
GND
X2
VDD
GND
50M
8 pin SOIC
25M
MK2011
Fast Ethernet Clock Source
MDS 2011 B
3
Revision 120597
Printed 11/15/00
MicroClock Division of ICS1271
Parkmoor Ave.San JoseCA95126(408)295-9800tel(408)295-9818fax
I C R O
C
LOC K
Notes:
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.
2. Typical values are at 25C.
Electrical Specifications
Parameter
Conditions
Minimum
Typical
Maximum
Units
ABSOLUTE MAXIMUM RATINGS (note 1)
ABSOLUTE MAXIMUM RATINGS (note 1)
Supply Voltage, VDD
Referenced to GND
7
V
Inputs
Referenced to GND
-0.5
VDD+.5V
V
Clock Outputs
Referenced to GND
-0.5
VDD+.5V
V
Ambient Operating Temperature
0
70
C
Soldering Temperature
Max of 20 seconds
260
C
Storage temperature
-65
150
C
DC CHARACTERISTICS (at 5.0V unless otherwise noted)
DC CHARACTERISTICS (at 5.0V unless otherwise noted)
DC CHARACTERISTICS (at 5.0V unless otherwise noted)
Operating Voltage, VDD
4.5
5.5
V
Input High Voltage, VIH, input clock only
Clock input
3.5
2.5
V
Input Low Voltage, VIL, input clock only
Clock input
2.5
1.5
V
Output High Voltage, VOH
IOH=-4mA
VDD-0.4
V
Output High Voltage, VOH
IOH=-25mA
2.4
V
Output Low Voltage, VOL
IOL=25mA
0.4
V
Operating Supply Current, IDD, 5V
No Load
19
mA
Operating Supply Current, IDD, 3.3V
No Load
10
mA
Input Capacitance
7
pF
Actual Mean Frequency versus Target
With exact crystal
0
ppm
AC CHARACTERISTICS
Input Clock or Crystal Frequency
20.0000
MHz
Input Crystal Accuracy
50
ppm
Input Clock Duty Cycle, 20.000MHz
Time above 2.5V
20
80
%
Output Clock Rise Time
0.8 to 2.0V
1.5
ns
Output Clock Fall Time
2.0 to 0.8V
1.5
ns
Output Clock Duty Cycle
Time above 1.5V
45
50
55
%
Absolute Clock Period Jitter, 20 MHz output
-400
250
400
ps
Absolute Clock Period Jitter, 50, 25 MHz clocks
-300
150
300
ps
One Sigma Clock Period Jitter
All outputs
70
ps
MK2011
Fast Ethernet Clock Source
MDS 2011 B
4
Revision 120597
Printed 11/15/00
MicroClock Division of ICS1271
Parkmoor Ave.San JoseCA95126(408)295-9800tel(408)295-9818fax
I C R O
C
LOC K
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.
Package Outline and Package Dimensions
Inches
Inches
Millimeters
Millimeters
Symbol
Min
Max
Min
Max
A
0.055
0.068
1.397
1.7272
b
0.013
0.019
0.330
0.483
D
0.185
0.200
4.699
5.080
E
0.150
0.160
3.810
4.064
H
0.225
0.245
5.715
6.223
e .050 BSC
.050 BSC
1.27 BSC
1.27 BSC
h
0.015
0.381
Q
0.004
0.01
0.102
0.254
8 pin SOIC
Ordering Information
Part/Order Number
Marking
Package
Temperature
MK2011S
MK2011S
8 pin SOIC
0-70C
MK2011STR
MK2011S
Add tape and reel
0-70C
c
A
b
D
E
H
e
h x 45
Q
Pin 1
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