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 PhaseLocked 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
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
X2
Voltage
Controlled
Crystal
Oscillator
PLL/Clock
Synthesis
Circuitry
Output
Buffer
27MHz
Pin Assignment
MK2727
Low Cost 27 MHz VCXO
MK2727
X1
VDD
VIN
GND
1 8
2
3
4
X2
7
GND
6
VDD
5
CLK
8 pin (150 mil) SOIC
Pin Descriptions
Number Name Description
1 X1 Crystal connection. Connect to a pullable 13.5 MHz crystal.
2 VDD VDD. Connect to +5V.
3 VIN Voltage input to VCXO. Zero to 3V analog input which controls the frequency of the VCXO.
4 GND Connect to ground.
5 CLK 27 MHz clock output.
6 VDD VDD. Connect to +5V.
7 GND Connect to ground.
8 X2 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
ABSOLUTE MAXIMUM RATINGS (note 1)
DC CHARACTERISTICS (VDD = 5.0V unless noted)
AC CHARACTERISTICS (VDD = 5.0V unless noted)
exposure to levels above the operating limits but below the Absolute Maximums may affect device reliability.
2. With a MicroClock approved pullable crystal.
Low Cost 27 MHz VCXO
Electrical Specifications
Parameter Conditions Minimum Typical Maximum Units
Supply voltage, VDD Referenced to GND 7 V
Inputs and Clock Outputs Referenced to GND -0.5 VDD+0.5 V
Ambient Operating Temperature 0 70 °C
Soldering Temperature Max of 10 seconds 260 °C
Storage temperature -65 150 °C
Operating Voltage, VDD 4.75 5.25 V
Output High Voltage, VOH IOH=-25mA 2.4 V
Output Low Voltage, VOL IOL=25mA 0.4 V
Output High Voltage, VOH, CMOS level IOH=-8mA VDD-0.4 V
Operating Supply Current, IDD No Load 20 mA
Short Circuit Current ±100 mA
VIN, VCXO control voltage 0 3 V
Input Crystal Frequency 13.50000 MHz
Input Crystal Accuracy ±30 ppm
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 At 1.4V 40 50 60 %
Maximum Absolute Jitter, short term 200 ps
27 MHz output pullability, note 2 0V ≤ VIN ≤ 3V ±100 ppm
Notes: 1. Stresses beyond those listed under Absolute Maximum Ratings could cause permanent damage to the device. Prolonged
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
Package Outline and Package Dimensions
Inches
Millimeters
8 pin SOIC
E H
Pin 1
D
h x 45°
MK2727
Low Cost 27 MHz VCXO
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
h 0.015 0.381
Q 0.004 0.01 0.102 0.254
Q
A
c
e
b
Ordering Information
Part/Order Number Marking Shipping packaging Package Temperature
MK2727S MK2727S tubes 8 pin SOIC 0-70°C
MK2727STR MK2727S tape and reel 8 pin SOIC 0-70°C
CHANGE HISTORY
Version Date first published Status Comments
A 12/12/96 Advance Original
B 12/2/97 Released 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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