The MK2722 is a low cost, low jitter, high performance
clock synthesizer designed for Sigma Designs’ MPEG
decoder systems. Using analog Phase-Locked Loop
(PLL) techniques, the device accepts a 27 MHz crystal
or clock input to produce multiple output clocks. The
power down pin turns off the device, drawing less than
100 µA.
ICS offers a wide variety of clock synthesizers for
desktop and portable computers, and multimedia
systems. Consult ICS to eliminate crystals and
oscillators from your board.
Features
• Packaged in 16 pin narrow (150 mil) SOIC
• Uses 27 MHz crystal or clock input
• Zero ppm synthesis error in all clocks (audio clocks
exactly track 27 MHz video clock)
• Audio clock supports 32, 44.1, and 48kHz
sampling rates at 256X and 384X
• Power down turns off chip
• Low jitter
• Total of four output clocks
• 25 mA output drive capability at TTL levels
• 5V±10% supply voltage (contact ICS for
3.3V operation)
• Advanced, low power, sub-micron CMOS process
Block Diagram
VDD
3
GND
2
PD
AS1:0
2
Clock
Synthesis and
Control Circuitry
Output
Buffer
Output
Buffer
Output
Buffer
ACLK
2
BS1:0
BCLK
BCLK/2
27 MHz crystal
or clock
X1
Crystal
Oscillator
X2
Output
Buffer
27.0000 MHz
MDS 2722 B
1
Revision 020802
Integrated Circuit Systems, Inc. • 525 Race Street • San Jose • CA • 95126 • (408)295 9800tel • www.icst.com
MK2722
Sigma Designs Clock Source
Pin Assignment
ACLK Decoding Table (MHz)
AS1
pin 12
0
0
0
1
1
1
AS0
pin 8
0
M
1
0
M
1
ACLK
pin 7
12.288
18.432
16.9344
11.2896
12.288
8.192
VDD
X2
X1
VDD
GND
BS1
ACLK
AS0
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
BS0
PD
27M
VDD
AS1
GND
BCLK/2
BCLK
BCLK Decoding Table (MHz)
BS1
pin 6
0
0
1
1
BS0
pin 16
0
1
0
1
BCLK
pin 9
40.5
50
28.6364
40
BCLK/2
pin 10
20.25
25
14.3182
20
16 pin narrow (150 mil) SOIC
Pin Descriptions
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Name
VDD
X2
X1
VDD
GND
BS1
ACLK
AS0
BCLK
BCLK/2
GND
AS1
VDD
27M
PD
BS0
Type
I
XO
XI
P
P
I
O
TI
O
O
P
I
P
O
I
I
Description
Connect to +5V.
Crystal connection. Connect to 27 MHz crystal. Leave unconnected for clock input.
Crystal connection. Connect to 27 MHz crystal or clock.
Connect to +5V.
Connect to ground.
Select 1 for BCLK. Determines BCLK outputs per table above. Internal pull-up.
Audio Clock output. Determined by status of AS1, AS0 per table above.
Select 0 for ACLK. Determines ACLK output per table above.
BCLK output. Determined by status of BS1, BS0 per table above.
BCLK divided by two output. Determined by status of BS1, BS0 per table above.
Connect to ground.
Select 1 for ACLK. Determines ACLK output per table above. Internal pull-up.
Connect to +5V.
27.0000 MHz buffered crystal clock output.
Power Down. Active low. Clocks stop low. Internal pull-up.
Select 0 for BCLK. Determines BCLK outputs per table above. Internal pull-up.
Key: I = Input, TI = Tri-level input, O = output, P = power supply connection
MDS 2722 B
2
Revision 020802
Integrated Circuit Systems, Inc. • 525 Race Street • San Jose • CA • 95126 • (408)295 9800tel • www.icst.com
MK2722
Sigma Designs Clock Source
Electrical Specifications
Parameter
Conditions
Minimum
ABSOLUTE MAXIMUM RATINGS (Note 1)
Supply voltage, VDD
Referenced to GND
Inputs and Clock Outputs
Referenced to GND
-0.5
Ambient Operating Temperature
0
Soldering Temperature
Max of 10 seconds
Storage temperature
-65
DC CHARACTERISTICS (VDD = 5V unless noted)
Operating Voltage, VDD
4.5
Input High Voltage, VIH
2
Input Low Voltage, VIL
Output High Voltage, VOH
IOH=-4mA
VDD-0.4
Output Low Voltage, VOL
IOL=25mA
Operating Supply Current, IDD, 5.0V
No Load
Power Down Supply Current, IDDPD, 5V
No Load, note 2
Short Circuit Current
Each output
Input Capacitance
On chip pull-up resistor
Pins 6, 8, 12, 15, and 16
AC CHARACTERISTICS (VDD = 5V unless noted)
Input Frequency
Input Crystal Accuracy
Frequency Error, all clocks
Output Clock Rise Time
0.8 to 2.0V
Output Clock Fall Time
2.0 to 0.8V
Output Clock Duty Cycle
At 1.4V
40
Maximum Absolute Jitter, short term
Typical
Maximum
Units
V
V
°C
°C
°C
V
V
V
V
V
mA
µA
mA
pF
kΩ
MHz
ppm
ppm
ns
ns
%
ps
7
VDD+0.5
70
260
150
5
5.5
0.8
0.4
30
25
±50
7
250
27.000
±30
0
1.5
1.5
60
50
200
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 AS1=AS0=BS1=BS0=VDD
External Components
The MK2722 requires a minimum number of external components for proper operation. Decoupling capacitors of
0.1µF should be connected between VDD and GND (pins 4 and 5, 13 and 11), as close to the MK2722 as possible.
A series termination resistor of 33Ω may be used for each clock output. If a clock input is not used, a 27 MHz
fundamental mode crystal must be connected as close to the chip as possible. Crystal capacitors should be
connected from pins X1 to ground and X2 to ground. The value (in pF) of these crystal capacitors should be = (CL -
12)*2, where C L is the crystal load capacitance in pF. So for a crystal with 16pF load capacitance, the crystal
capacitors should be 8pF each.
MDS 2722 B
3
Revision 020802
Integrated Circuit Systems, Inc. • 525 Race Street • San Jose • CA • 95126 • (408)295 9800tel • www.icst.com
MK2722
Sigma Designs Clock Source
Package Outline and Package Dimensions
16 pin SOIC narrow
Inches
Symbol Min
Max
A
0.055 0.070
b
0.013 0.019
c
0.007 0.010
D
0.385 0.400
E
0.150 0.160
H
0.225 0.245
e
.050 BSC
h
0.016
Q
0.004 0.01
Millimeters
Min
Max
1.397 1.778
0.330 0.483
0.191 0.254
9.779 10.160
3.810 4.064
5.715 6.223
1.27 BSC
0.406
0.102 0.254
E
H
h x 45°
D
Q
e
b
c
A
Ordering Information
Part/Order Number
MK2722-01S
MK2722-01STR
Marking
MK2722-01S
MK2722-01S
Shipping packaging
tubes
tape and reel
Package
16 pin SOIC
16 pin SOIC
Temperature
0-70°C
0-70°C
While the information presented herein has been checked for both accuracy and reliability, 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 2722 B
4
Revision 020802
Integrated Circuit Systems, Inc. • 525 Race Street • San Jose • CA • 95126 • (408)295 9800tel • www.icst.com
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
