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Description
The MK2772-01 is a low cost, low jitter, high
performance VCXO and clock synthesizer for set-
top boxes. 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 13.5 MHz crystal input to
produce multiple output clocks. All clocks are
frequency locked to the 27.00MHz output (and to
each other) with zero ppm error. The MK2772
includes a glitch-free multiplexer to switch input
sources during operation.
MicroClock manufactures the largest variety of
Set-Top Box and multimedia clock synthesizers
for all applications. Consult MicroClock to
eliminate VCXOs, crystals and oscillators from
your board.
MK2772-01
VCXO and Set-Top Clock Source
Features
• Packaged in 20 pin SOIC
• Uses an inexpensive 13.5 MHz crystal
• On-chip VCXO (patented) with pull range
of 200ppm (minimum)
• Ability to switch input sources “on-the-fly”
• VCXO tuning voltage of 0 to 3V
• Zero ppm synthesis error (patented) in all
clocks. All exactly track 27MHz VCXO
• All clocks are frequency locked. All will vary the
same amount (in ppm) as the VCXO
• Selectable Audio clock for 256x, 384x, and 512x.
• 25mA output drive capability at TTL levels
• Advanced, low power, sub-micron CMOS process
• 5V operating voltage
Block Diagram
VDD GND
3
3
2
Clock
Synthesis
Circuitry
Output
Buffer
Output
Buffer
Output
Buffer
Output
Buffer
Voltage Controlled
Crystal Oscillator
and x2 PLL
ACS1:0
Audio Clock
16.6667 MHz
11.0592 MHz
INMUXSEL
EXTCLKIN
VIN
13.5 MHz
pullable
crystal
X1
3.6864 MHz
3
X2
deglitched
mux
Output
Buffers
27.000 MHz
1
Revision 012098
Printed 11/16/00
Integrated Circuit Systems, Inc.•525 Race Street•San Jose•CA•95126•(408)295-9800tel•www.icst.com
MDS 2772-01 B
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Pin Assignment
ACS1
X2
X1
VDD
VIN
VDD
GND
16.67M
3.68M
ACLK
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
ACS0
EXTCLKIN
27M
GND
27M
VDD
GND
27M
11.06M
INMUXSEL
MK2772-01
VCXO and Set-Top Clock Source
Audio Clock Select
ACS1 ACS0 ACLK (MHz)
0
0
8.192
0
M
16.384
0
1
11.2896
M
0
16.9344
M
M
22.5792
M
1
18.432
1
0
12.288
1
M
24.576
1
1
5.6448
Input Source Select
INMUXSEL
0
1
27 MHz Input
EXTCLKIN
Internal VCXO
Pin Descriptions
Number
Name
1
ACS1
2
X2
3
X1
4
VDD
5
VIN
6
VDD
7
GND
8
16.67M
9
3.68M
10
ACLK
11
INMUXSEL
12
11.06M
13
27M
14
GND
15
VDD
16
27M
17
GND
18
27M
19
EXTCLKIN
20
ACS0
Type
TI
X
X
P
VI
P
P
O
O
O
I
O
O
P
P
O
P
O
I
TI
Description
Audio Clock Select 1. Determines ACLK frequency, as per table above.
Crystal connection. Connect to a pullable 13.5 MHz crystal.
Crystal connection. Connect to a pullable 13.5 MHz crystal.
Connect to +5V, and other VDDs.
Voltage Input to VCXO. Zero to 3V signal which controls the frequency of the VCXO.
Connect to +5V.
Connect to ground.
16.6667 MHz processor clock output.
3.6864 MHz clock output.
Audio Clock Output determined by ACS1,0. Per table above.
Input Multiplexer Select. Selects either the internal VCXO/PLL output, or the clock on pin 19.
11.0592 MHz clock output.
27.00 MHz clock output.
Connect to ground.
Connect to +5V.
27.00 MHz clock output.
Connect to ground.
27.00 MHz clock output.
External Clock Input. Connect an external 27 MHz clock to this pin for glitch free switching.
Audio Clock Select 0. Determines ACLK frequency, as per table above.
Key: I = Input, TI = tri-level input, VI = VCXO input, O = output, P = power supply connection, X = crystal connection
2
Revision 012098
Printed 11/16/00
Integrated Circuit Systems, Inc.•525 Race Street•San Jose•CA•95126•(408)295-9800tel•www.icst.com
MDS 2772-01 B
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Electrical Specifications
Parameter
Supply voltage, VDD
Inputs and Clock Outputs
Ambient Operating Temperature
Soldering Temperature
Storage temperature
Operating Voltage, VDD
Input High Voltage, VIH, X1 pin only
Input Low Voltage, VIL, X1 pin only
Input High Voltage, VIH
Input High Voltage, VIH
Input Low Voltage, VIL
Output High Voltage, VOH
Output Low Voltage, VOL
Output High Voltage, VOH, CMOS level
Operating Supply Current, IDD
Pull-up Resistor value
Input Capacitance
Frequency synthesis error
VIN, VCXO control voltage
Conditions
MK2772-01
VCXO and Set-Top Clock Source
Minimum
Typical
Maximum
7
VDD+0.5
70
260
150
5.25
2.5
2.5
1.5
Units
V
V
°C
°C
°C
V
V
V
V
V
V
V
V
V
mA
Ω
pF
ppm
V
ABSOLUTE MAXIMUM RATINGS (note 1)
Referenced to GND
Referenced to GND
Max of 10 seconds
-65
4.75
3.5
ACS1, ACS0
INMUXSEL
IOH=-25mA
IOL=25mA
IOH=-8mA
No Load, note 2
pin 11 only
All clocks as shown
0
VDD-0.5
2
0.8
2.4
0.4
VDD-0.4
45
250k
7
0
-0.5
0
DC CHARACTERISTICS (VDD = 5.0V unless noted)
1
3
AC CHARACTERISTICS (VDD = 5.0V unless noted)
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
60
%
Maximum Absolute Jitter, short term
300
ps
27 MHz output pullability, note 3
0V
≤
VIN
≤
3V
±100
ppm
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. With ACLK at 12.288 MHz.
3. With a recommended crystal.
External Components/Crystal Selection
The MK2772-01 requires a minimum number of external components for proper operation. Decoupling capacitors of 0.1µF
should be connected between VDD (pin 15) and GND (14), and between VDD (4) and GND (7), as close to the MK2772-01 as
possible. A series termination resistor of 33Ω may be used for each clock output. The input crystal must be connected as close to the
chip as possible. The 13.5 MHz input crystal should be a parallel mode, pullable, AT cut with 14.0pF load capacitance. See
Application Note MAN05 for more details on crystal selection and layout. Recommended crystal is from Ecliptek Corporation,
P/N ECX-4665-13.500M. Contact Ecliptek at 714 433 1200tel, 714 433 1234fax.
3
Revision 012098
Printed 11/16/00
Integrated Circuit Systems, Inc.•525 Race Street•San Jose•CA•95126•(408)295-9800tel•www.icst.com
MDS 2772-01 B
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Package Outline and Package Dimensions
MK2772-01
VCXO and Set-Top Clock Source
20 pin SOIC
Symbol
A
b
c
D
E
H
e
h
Q
Inches
Min
Max
0.092 0.104
0.014 0.019
0.009 0.012
0.490 0.512
0.290 0.300
0.394 0.419
.050 BSC
0.016
0.003 0.011
Millimeters
Min
Max
2.3368 2.6416
0.356
0.483
0.229
0.305
12.446 13.005
7.366
7.620
10.008 10.643
1.27 BSC
0.406
0.076
0.279
E
H
D
Q
e
b
c
h x 45°
A
Ordering Information
Part/Order Number
MK2772-01S
MK2772-01STR
Marking
MK2772-01S
MK2772-01S
Shipping packaging
tubes
tape and reel
Package
20 pin SOIC
20 pin SOIC
Temperature
0-70°C
0-70°C
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.
4
Revision 012098
Printed 11/16/00
Integrated Circuit Systems, Inc.•525 Race Street•San Jose•CA•95126•(408)295-9800tel•www.icst.com
MDS 2772-01 B
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