MK2727
Low Cost 27 MHz VCXO
Description
The MK2727 is MicroClock’s lowest cost, low
jitter, high performance VCXO and PLL clock
synthesizer designed to replace expensive 27MHz
VCXOs. The on-chip Voltage Controlled Crystal
Oscillator accepts a 0 to 3V input voltage to cause
the output clocks to vary by ±100 ppm. Using
MicroClock’s patented VCXO and analog Phase-
Locked Loop (PLL) techniques, the device uses an
inexpensive external 13.5 MHz pullable crystal
input to produce a
27 MHz output clock.
MicroClock manufactures the largest variety of
Set-Top Box and multimedia clock synthesizers
for all applications. If more clock outputs are
needed, see the MK2731 or MK277x family of
parts. Consult MicroClock to eliminate VCXOs,
crystals and oscillators from your board.
Features
• Packaged in 8 pin narrow SOIC
• Uses an inexpensive 13.500 MHz external crystal
• On-chip VCXO (patented) with pull range of
200ppm (minimum)
• VCXO tuning voltage of 0 to 3V
• 25mA output drive capability at TTL levels
• Advanced, low power, sub-micron CMOS process
• 5V operating voltage
Block Diagram
VIN
X1
13.5 MHz
pullable
crystal
X2
Voltage
Controlled
Crystal
Oscillator
PLL/Clock
Synthesis
Circuitry
Output
Buffer
27MHz
MDS 2727 B
1
Revision 111600
Printed 11/16/00
Integrated Circuit Systems, Inc.•525 Race Street•San Jose•CA•95126•(408)295-9800tel•www.icst.com
MK2727
Low Cost 27 MHz VCXO
Pin Assignment
MK2727
X1
VDD
VIN
GND
1
2
3
4
8
7
6
5
X2
GND
VDD
CLK
8 pin (150 mil) SOIC
Pin Descriptions
Number
1
2
3
4
5
6
7
8
Name
X1
VDD
VIN
GND
CLK
VDD
GND
X2
Description
Crystal connection. Connect to a pullable 13.5 MHz crystal.
VDD. Connect to +5V.
Voltage input to VCXO. Zero to 3V analog input which controls the frequency of the VCXO.
Connect to ground.
27 MHz clock output.
VDD. Connect to +5V.
Connect to ground.
Crystal connection. Connect to a pullable 13.5 MHz crystal.
MDS 2727 B
2
Revision 111600
Printed 11/16/00
Integrated Circuit Systems, Inc.•525 Race Street•San Jose•CA•95126•(408)295-9800tel•www.icst.com
MK2727
Low Cost 27 MHz VCXO
Electrical Specifications
Parameter
Supply voltage, VDD
Inputs and Clock Outputs
Ambient Operating Temperature
Soldering Temperature
Storage temperature
Operating Voltage, VDD
Output High Voltage, VOH
Output Low Voltage, VOL
Output High Voltage, VOH, CMOS level
Operating Supply Current, IDD
Short Circuit Current
VIN, VCXO control voltage
Input Crystal Frequency
Input Crystal Accuracy
Output Clock Rise Time
Output Clock Fall Time
Output Clock Duty Cycle
Maximum Absolute Jitter, short term
27 MHz output pullability, note 2
Notes:
Conditions
Referenced to GND
Referenced to GND
Max of 10 seconds
-65
4.75
2.4
VDD-0.4
20
±100
0
13.50000
0.8 to 2.0V
2.0 to 0.8V
At 1.4V
0V
≤
VIN
≤
3V
±30
1.5
1.5
60
3
Minimum
Typical
Maximum
7
VDD+0.5
70
260
150
5.25
0.4
Units
V
V
°C
°C
°C
V
V
V
V
mA
mA
V
MHz
ppm
ns
ns
%
ps
ppm
ABSOLUTE MAXIMUM RATINGS (note 1)
-0.5
0
DC CHARACTERISTICS (VDD = 5.0V unless noted)
IOH=-25mA
IOL=25mA
IOH=-8mA
No Load
AC CHARACTERISTICS (VDD = 5.0V unless noted)
40
±100
50
200
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. With a MicroClock approved pullable crystal.
External Components
The MK2727 requires a minimum number of external components for proper operation. A decoupling
capacitor of 0.1µF should be connected between VDD and GND on pins 2 and 4, as close to the MK2727
as possible. A series termination resistor of 33Ω may be used for the clock output. The input crystal must be
connected as close to the chip as possible. The input crystal should be a parallel mode, pullable, AT cut,
13.5MHz, with 14pF load capacitance. Consult MicroClock for recommended suppliers. IMPORTANT -
read application note MAN05 before laying out the PCB.
MDS 2727 B
3
Revision 111600
Printed 11/16/00
Integrated Circuit Systems, Inc.•525 Race Street•San Jose•CA•95126•(408)295-9800tel•www.icst.com
MK2727
Low Cost 27 MHz VCXO
Package Outline and Package Dimensions
8 pin SOIC
Symbol
A
b
D
E
H
e
h
Q
Inches
Min
Max
0.055 0.068
0.013 0.019
0.185 0.200
0.150 0.160
0.225 0.245
.050 BSC
0.015
0.004
0.01
Millimeters
Min
Max
1.397 1.7272
0.330
0.483
4.699
5.080
3.810
4.064
5.715
6.223
1.27 BSC
0.381
0.102
0.254
E
Pin 1
H
D
Q
e
b
c
h x 45°
A
Ordering Information
Part/Order Number
MK2727S
MK2727STR
Marking
MK2727S
MK2727S
Shipping packaging
tubes
tape and reel
Package
8 pin SOIC
8 pin SOIC
Temperature
0-70°C
0-70°C
CHANGE HISTORY
Version Date first published
A
12/12/96
B
12/2/97
Status
Advance
Released
Comments
Original
Updated logo & address. Corrected pkg height.
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 2727 B
4
Revision 111600
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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