MK2745-24
DVD/MPEG Clock Source
MDS 2745-24 B
1
Revision 100898
Printed 11/16/00
MicroClock Division of ICS1271
Parkmoor Ave.San JoseCA95126(408)295-9800tel(408)295-9818fax
I C R O
C
LOC K
The MK2745-24 is a low cost, low jitter, high
performance clock synthesizer for DVD and other
MPEG 2 based applications. Using analog Phase-
Locked Loop (PLL) techniques, the device accepts
a 27.00 MHz fundamental mode crystal or clock
input to produce multiple audio output clocks, a
processor clock, and two 27 MHz clocks. The
audio clocks are frequency locked to the
27.00 MHz using our patented zero ppm error
techniques, allowing audio and video to track
exactly, thereby eliminating the need for large
buffer memory.
MicroClock manufactures the largest variety of
DVD, Set-Top Box, and multimedia clock
synthesizers for all applications. Consult
MicroClock to eliminate crystals and oscillators
from your board.
Block Diagram
Description
Features
Packaged in 16 pin narrow (150 mil) SOIC
Ideal for AuraVision's notebook DVD solutions
Patented zero ppm audio clock error for exact
audio clock sampling rates, plus 32x and 256x
clocks of the sampling frequencies
Selectable audio sampling frequencies support
32, 44.1, 48 and 96 kHz in most DACs
27.00 MHz fundamental crystal or clock input
Selectable processor frequencies
Two clocks of 27 MHz
Zero ppm error in all clocks
25mA output drive capability at TTL levels
Advanced, low power, sub-micron CMOS process
3.0V to 5.5V operating voltage
See also the MK2712 for NTSC/PAL clocks
Crystal
Oscillator
VDD
GND
Clock Synthesis
and Control
Circuitry
ACLK/256
Output
Buffer
27 MHz clock
or crystal
Output
Buffer
27.0 MHz
Output
Buffer
PCLK
Output
Buffer
ACLK/8
Output
Buffer
27.0 MHz
X2
X1
ACS1:0
/
2
PCS
2
3
Output
Buffer
ACLK
8
256
MK2745-24
DVD/MPEG Clock Source
MDS 2745-24 B
2
Revision 100898
Printed 11/16/00
MicroClock Division of ICS1271
Parkmoor Ave.San JoseCA95126(408)295-9800tel(408)295-9818fax
I C R O
C
LOC K
Pin Descriptions
Audio Clocks Selection Table (in MHz)
Key: I = Input, O = output, P = power supply connection
Pin Assignment
Number
Name
Type
Description
1
GND
P
Connect to ground.
2
X2
XO
Crystal connection. Connect to 27 MHz crystal. Leave unconnected for clock input.
3
X1/ICLK
XI
Crystal connection. Connect to 27 MHz crystal or connect to 27 MHz input clock.
4
VDD
P
Connect to +3.3 V or +5 V. Must be same as other VDD.
5
GND
P
Connect to ground.
6
27M
O
27.00 MHz clock output.
7
ACS0
I
Audio Clock Select 0. Selects audio clocks per table above.
8
ACLK/8
O
Audio Clock divided by 8 output. Determined by status of ACS1, ACS0. See table above.
9
ACLK/256
O
Audio Clock divided by 256 output. Determined by status of ACS1, ACS0. See table above.
10
PCS
I
Processor Clock Select pin. Selects PCLK per table above.
11
ACLK
O
Audio Clock output. Determined by status of ACS1, ACS0. See table above.
12
GND
P
Connect to ground.
13
VDD
P
Connect to +3.3 V or +5 V. Must be same as other VDD.
14
PCLK
O
Processor Clock output. Determined by status of PCS. See table above.
15
27M
O
27.00 MHz clock output.
16
ACS1
I
Audio Clock Select 1. Selects audio clocks per table above.
MK2745-24
16 pin (150 mil) SOIC
0 = connect directly to ground
1 = connect directly to VDD
1
16
2
3
4
15
14
13
VDD
GND
X2
VDD
ACLK
5
6
7
8
12
11
10
9
ACLK/8
PCLK
X1/ICLK
PCS
GND
ACS1
27M
27M
GND
ACLK/256
ACS0
ACS1 ACS0
ACLK
ACLK/8
ACLK/256
0
0
24.576
3.072
96.0 kHz
0
1
11.2896
1.4112
44.1 kHz
1
0
8.192
1.024
32.0 kHz
1
1
12.288
1.536
48.0 kHz
PCS
PCLK
0
40
1
60
Processor Clock (MHz)
MK2745-24
DVD/MPEG Clock Source
MDS 2745-24 B
3
Revision 100898
Printed 11/16/00
MicroClock Division of ICS1271
Parkmoor Ave.San JoseCA95126(408)295-9800tel(408)295-9818fax
I C R O
C
LOC K
Parameter
Conditions
Minimum
Typical
Maximum
Units
ABSOLUTE MAXIMUM RATINGS (note 1)
ABSOLUTE MAXIMUM RATINGS (note 1)
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 20 seconds
260
C
Storage temperature
-65
150
C
DC CHARACTERISTICS (VDD = 5.0V unless noted)
DC CHARACTERISTICS (VDD = 5.0V unless noted)
Operating Voltage, VDD
3
5.5
V
Input High Voltage, VIH, X1/ICLK pin only
VDD/2 + 1
VDD/2
V
Input Low Voltage, VIL, X1/ICLK pin only
VDD/2
VDD/2 - 1
V
Input High Voltage, VIH
2
V
Input Low Voltage, VIL
0.8
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, note 2
37
mA
Short Circuit Current
Each output
100
mA
Input Capacitance
7
pF
AC CHARACTERISTICS (VDD = 5.0V unless noted)
AC CHARACTERISTICS (VDD = 5.0V unless noted)
Input Frequency
27.000
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
60
%
Frequency synthesis error, all clocks
0
1
ppm
Absolute Jitter, short term
Variation from mean
200
ps
Electrical Specifications
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 VDD=3.3V, processor clock at 60MHz, and ACLK at 12.288MHz.
External Components
The MK2745-24 requires a minimum number of external components for proper operation. Decoupling
capacitors of 0.1F should be connected between VDD and GND (on pins 4 and 5, and pins 13 and 12),
as close to the MK2745-24 as possible. A series termination resistor of 33
may be used for each clock
output. If a clock input is not used, the 27.00 MHz crystal must be connected as close to the chip as
possible. The crystal should be a fundamental mode (do not use third overtone), parallel resonant, 50ppm
or better. Crystal capacitors should be connected from pins X1 to ground and X2 to ground. The value of
these capacitors is given by the following equation, where C
L
is the crystal load capacitance: Crystal caps
(pF) = (C
L
-6) x 2. So for a crystal with 16pF load capacitance, two 20pF caps should be used.
MK2745-24
DVD/MPEG Clock Source
MDS 2745-24 B
4
Revision 100898
Printed 11/16/00
MicroClock Division of ICS1271
Parkmoor Ave.San JoseCA95126(408)295-9800tel(408)295-9818fax
I C R O
C
LOC K
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.
Package Outline and Package Dimensions
Ordering Information
Part/Order Number
Marking
Shipping packaging
Package
Temperature
MK2745-24S
MK2745-24S
tubes
16 pin narrow SOIC
0-70C
MK2745-24STR
MK2745-24S
tape and reel
16 pin narrow SOIC
0-70C
16 pin SOIC narrow
Inches
Inches
Millimeters
Millimeters
Symbol
Min
Max
Min
Max
A
0.055
0.070
1.397
1.778
b
0.013
0.019
0.330
0.483
c
0.007
0.010
0.191
0.254
D
0.385
0.400
9.779
10.160
E
0.150
0.160
3.810
4.064
H
0.225
0.245
5.715
6.223
e .050 BSC
.050 BSC
1.27 BSC
1.27 BSC
h
0.016
0.406
Q
0.004
0.01
0.102
0.254
b
D
E
H
e
Q
c
h x 45
A
Rev. 04218, version A . First publication, Preliminary.
Rev. 10088, version B. Production.
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