synthesizer designed to replace expensive 13.5, 27,
or 54MHz VCXOs. The patented on-chip
Voltage Controlled Crystal Oscillator accepts a
0 to 3.3 V input voltage to cause the output clocks
to vary by ±100 ppm. Using our patented VCXO
and analog/digital Phase-Locked Loop (PLL)
techniques, the device uses an inexpensive external
13.5 MHz pullable crystal input to produce output
clocks of 13.5 MHz, 27 MHz, and 54 MHz .
The MK3720A is a drop-in replacement to the
earlier MK3720S.
Features
• Packaged in 8 pin SOIC
• 3.3 V only operating voltage
• Output clocks of 54, 27, and 13.5MHz
• Uses an inexpensive 13.500 MHz external crystal
• On-chip patented VCXO with pull range
of 200ppm (minimum)
• VCXO tuning voltage of 0 to 3.3 V
• 12 mA output drive capability at TTL levels
• Advanced, low power, sub-micron CMOS process
• The A version is the latest, manufactured in a smaller
geometry process. The MK3720A gives a wider pull
range than the MK3720S, and so is recommended
for all new designs, and cost reductions of existing
designs.
Block Diagram
VIN
13.5 MHz
pullable
crystal
X1
Output
Buffer
Voltage
Controlled
Crystal
Oscillator
PLL/Clock
Synthesis
Circuitry
Output
Buffer
Output
Buffer
54 MHz Clock
27 MHz Clock
13.5 MHz Clock
X2
1
Revision 053100
Printed 11/16/00
Integrated Circuit Systems, Inc. •525 Race Street • San Jose • CA• 95126• (408)295-9800tel • www.icst.com
MDS 3720 D
MK3720
27 MHz and 54 MHz 3.3 Volt VCXO
Pin Assignment
MK3720
X1
VDD
VIN
GND
1
2
3
4
8
7
6
5
X2
27M
13.5M
54M
8 pin (150 mil) SOIC
Pin Descriptions
Number
1
2
3
4
5
6
7
8
Name
X1
VDD
VIN
GND
54M
13.5M
27M
X2
Description
Crystal connection. Connect to a pullable 13.5 MHz crystal.
VDD. Connect to +3.3 V.
Voltage input to VCXO. Zero to 3.3 V analog input which controls the frequency of the VCXO.
Connect to ground.
54 MHz VCXO clock output.
13.5 MHz VCXO clock output.
27 MHz VCXO clock output.
Crystal connection. Connect to a pullable 13.5 MHz crystal.
Pullable Crystal Specifications:
Correlation (load) Capacitance
C0/C1
ESR
Operating Temperature
Initial Accuracy
Temperature plus Aging Stability
14 pF
240 max
35
Ω
max
0 to 70 °C
±20 ppm
±50 ppm
2
Revision 053100
Printed 11/16/00
Integrated Circuit Systems, Inc. •525 Race Street • San Jose • CA• 95126• (408)295-9800tel • www.icst.com
MDS 3720 D
MK3720
27 MHz and 54 MHz 3.3 Volt 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
Output Clock Rise Time
Output Clock Fall Time
Output Clock Duty Cycle
Maximum Absolute Jitter, short term
Output pullability, note 2
Notes:
Conditions
Referenced to GND
Referenced to GND
Max of 10 seconds
-65
3.15
2.4
VDD-0.4
11
±50
0
13.50000
0.8 to 2.0V
2.0 to 0.8V
At 1.4V
0V
≤
VIN
≤
3.3 V
1.5
1.5
55
3.3
Minimum
Typical
Maximum
7
VDD+0.5
70
260
150
3.45
0.4
Units
V
V
°C
°C
°C
V
V
V
V
mA
mA
V
MHz
ns
ns
%
ps
ppm
ABSOLUTE MAXIMUM RATINGS (note 1)
-0.5
0
DC CHARACTERISTICS (VDD = 3.3 V unless noted)
IOH=-12mA
IOL=12mA
IOH=-4mA
No Load
AC CHARACTERISTICS (VDD = 3.3 V unless noted)
45
±100
50
100
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 an ICS approved pullable crystal. The MK3720A has a typical pull range of ±180 ppm.
External Components
The MK3720 requires a minimum number of external components for proper operation. A decoupling
capacitor of 0.01µF should be connected between VDD and GND on pins 2 and 4, as close to the
MK3720 as possible. A series termination resistor of 33
Ω
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, 13.5 MHz, with 14 pF load capacitance. Consult ICS for recommended suppliers.
IMPORTANT - read application note MAN05 before laying out the PCB.
3
Revision 053100
Printed 11/16/00
Integrated Circuit Systems, Inc. •525 Race Street • San Jose • CA• 95126• (408)295-9800tel • www.icst.com
MDS 3720 D
MK3720
27 MHz and 54 MHz 3.3 Volt VCXO
Package Outline and Package Dimensions
(
For current dimensional specifications, see JEDEC Publication No. 95.)
8 pin SOIC
Symbol
A
A1
B
E
INDEX
AREA
H
C
1
h x 45°
D
D
E
e
H
h
L
Inches
Min
Max
0.0532 0.0688
0.0040 0.0098
0.0130 0.0200
0.0075 0.0098
0.1890 0.1968
0.1497 0.1574
.050 BSC
0.2284 0.2440
0.0099 0.0195
0.0160 0.0500
Millimeters
Min
Max
1.35
1.75
0.10
0.24
0.33
0.51
0.19
0.24
4.80
5.00
3.80
4.00
1.27 BSC
5.80
6.20
0.25
0.50
0.41
1.27
A1
e
B
C
A
L
Ordering Information
Part/Order Number
MK3720A
MK3720ATR
MK3720S
MK3720STR
Marking
MK3720A
MK3720A
MK3720S
MK3720S
Shipping packaging
tubes
Tape and reel
tubes
Tape and reel
Package
8 pin SOIC
8 pin SOIC
8 pin SOIC
8 pin SOIC
Temperature
0-70 °C
0-70 °C
0-70 °C
0-70 °C
CHANGE HISTORY
Version Date first published
D
5/31/00
C
12/29/99
B
5/25/99
A
4/19/99
Status
Released
Preliminary
Preliminary
Comments
Added A version
Changed to JEDEC dimensions. Changed VDD to ±5%. Added Crystal specs.
Updated specs for crystal capacitance, IDD, jitter.
Original
While the information presented herein has been checked for both accuracy and reliability, Integrated Circuit Systems, Inc. (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.
4
Revision 053100
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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