Page 1
PRELIMINARY INFORMATION
MK3723
ICRO
C
LOCK
Description
The MK3723 is ICS/MicroClock’s lowest cost,
low jitter, high performance 3.3 volt VCXO
designed to replace expensive VCXO modules.
The 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
ICS/MicroClock’s patented VCXO techniques,
the device uses an inexpensive external pullable
crystal in the range of 16 - 28 MHz to produce a
VCXO output clock that is a divide by 2, 4, 6, or
8 or the crystal frequency.
ICS/MicroClock manufactures the largest variety
of Set-Top Box and multimedia clock synthesizers
for all applications. If more clock outputs are
needed, see the MK3732 or MK377x family of
parts. Consult ICS/MicroClock to eliminate
VCXOs, crystals and oscillators from your board.
Low Cost 3.3 Volt VCXO
Features
• Packaged in 8 pin SOIC
• 3.3 V only operating voltage
• 2 MHz to 14 MHz VCXO operation
• Ideal for 26 MHz from a 28 MHz crystal
• Uses an inexpensive external crystal
• On-chip VCXO (patented) with pull range of
200 ppm (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
• For frequencies between 16.2 MHz and 28 MHz
use the MK3721S. For higher than 28 MHz, use
the MK3732-05
Block Diagram
VIN
X1
16 -28 MHz
pullable crystal
X2
S1, S0
MDS 3723 A 1 Revision 082800
Integrated Circuit Systems, Inc. • 525 Race Street • San Jose •CA • 95126• (408)295-9800tel • www.icst.com
Voltage
Controlled
Crystal
Oscillator
÷N
Output
Buffer
VCXOCLK
Page 2
PRELIMINARY INFORMATION
MK3723
Pin Assignment
X1
VDD
VIN
GND
8 pin (150 mil) SOIC
Pin Descriptions
ICRO
C
MK3723
1 8
2
3
4
LOCK
X2
7
S1
6
VCXOCLK
5
S0
Low Cost 3.3 Volt VCXO
Divider Select Table
S1 S0 VCXOCLK (MHz)
0 0 Crystal ÷2
0 1 Crystal ÷4
1 0 Crystal ÷6
1 1 Crystal ÷8
0 = connect directly to ground
1 = connect directly to VDD
Number Name Description
1 X1 Crystal connection. Connect to a pullable 10 to 20 MHz crystal.
2 VDD VDD. Connect to + 3.3 V.
3 VIN Voltage input to VCXO. Zero to 3.3 V analog input which controls the frequency of the VCXO.
4 GND Connect to ground.
5 S0 Select pin for VCXO divider. See table above.
6 VCXOCLK VCXO clock output. Full CMOS output amplitude.
7 S1 Select pin for VCXO divider. See table above.
8 X2 Crystal connection. Connect to a pullable 16 to 28 MHz crystal.
Crystal Specifications
Correlation (load) capacitance 14 pF
Initial accuracy ±20 ppm maximum
Drift over temperature and aging ±50 ppm maximum
C0/C1 ratio 240 maximum
ESR 35 Ω maximum
MDS 3723 A 2 Revision 082800
Integrated Circuit Systems, Inc. • 525 Race Street • San Jose •CA • 95126• (408)295-9800tel • www.icst.com
Page 3
PRELIMINARY INFORMATION
ABSOLUTE MAXIMUM RATINGS (note 1)
DC CHARACTERISTICS (VDD = 3.3 V unless noted)
AC CHARACTERISTICS (VDD = 3.3 V unless noted)
exposure to levels above the operating limits but below the Absolute Maximums may affect device reliability.
2. With a ICS/MicroClock approved pullable crystal.
MK3723
ICRO
C
LOCK
Low Cost 3.3 Volt 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 3.15 3.45 V
Output High Voltage, VOH IOH=-12mA 2.4 V
Output Low Voltage, VOL IOL=12mA 0.4 V
Output High Voltage, VOH, CMOS level IOH=-4mA VDD-0.4 V
Operating Supply Current, IDD No Load 4 mA
Short Circuit Current ±50 mA
VIN, VCXO control voltage 0 3.3 V
Input Crystal Frequency 16 28 MHz
Input Crystal Accuracy ±30 ppm
VCXO Output Clock Frequency 2 14 MHz
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 VDD/2 40 50 60 %
Maximum Absolute Jitter, short term 100 ps
Output frequency pullability, note 2 0V ≤ VIN ≤ 3.3 V ±100 ±180 ppm
Notes: 1. Stresses beyond those listed under Absolute Maximum Ratings could cause permanent damage to the device. Prolonged
External Components
The MK3723 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
MK3723 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, with 14 pF load capacitance. See previous page for crystal specifications. Consult ICS for
recommended suppliers. IMPORTANT - read application note MAN05 before laying out the PCB.
MDS 3723 A 3 Revision 082800
Integrated Circuit Systems, Inc. • 525 Race Street • San Jose •CA • 95126• (408)295-9800tel • www.icst.com
Page 4
PRELIMINARY INFORMATION
Inches
Millimeters
MK3723
ICRO
C
LOCK
Low Cost 3.3 Volt VCXO
Package Outline and Package Dimensions
(For current dimensional specifications, see JEDEC Publication No. 95.)
8 pin SOIC
Symbol Min Max Min Max
A 0.0532 0.0688 1.35 1.75
A1 0.0040 0.0098 0.10 0.24
B 0.0130 0.0200 0.33 0.51
C 0.0075 0.0098 0.19 0.24
D 0.1890 0.1968 4.80 5.00
E 0.1497 0.1574 3.80 4.00
e
H 0.2284 0.2440 5.80 6.20
h 0.0099 0.0195 0.25 0.50
L 0.0160 0.0500 0.41 1.27
INDEX
AREA
A1
E H
D
A
C
e
B
L
Ordering Information
Part/Order Number Marking Shipping packaging Package Temperature
MK3723S MK3723S tubes 8 pin SOIC 0-70 °C
MK3723STR MK3723S tape and reel 8 pin SOIC 0-70 °C
While the information presented herein has been checked for both accuracy and reliability, Integrated Circuit Systems Incorporated (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.
MDS 3723 A 4 Revision 082800
Integrated Circuit Systems, Inc. • 525 Race Street • San Jose •CA • 95126• (408)295-9800tel • www.icst.com
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