eliminate crystals and oscillators from your board.
MK2742
MPEG/Set-Top Clock Source
Features
• Packaged in 16 pin narrow (150 mil) SOIC
• Pin compatible upgrade to MK2741 with:
- zero ppm audio clock error (-03, -04)
- new processor frequencies
- support for low cost codecs (-05,-06)
• Selectable audio sampling frequencies support
32 kHz, 44.1 kHz, and 48 kHz in most DACs
• 27.00 MHz crystal or clock input
• Selectable processor frequencies
• Fixed clocks of 13.5, 27, and 3.6864 MHz
• Zero ppm error in 13.5, 27, and 3.686 MHz clocks
• 25mA output drive capability at TTL levels
• Advanced, low power, sub-micron CMOS process
• 5V±10% operating voltage
Block Diagram
VDD
GND
2
2
3
2
Output
Buffer
AS1:0
PS2:0
27.00 MHz
clock or
crystal
X1
Audio Clock
Processor Clock
3.6864 MHz
Clock Synthesis
and Control
Circuitry
Output
Buffer
Output
Buffer
Output
Buffer
X2
Clock
Buffer/
Crystal
Oscillator
13.5 MHz
÷2
Output
Buffer
27.00 MHz
1
Revision 10277
Printed 10/27/97
MicroClock Division of ICS•1271 Parkmoor Ave.•San Jose•CA•95126•(408)295-9800tel•(408)295-9818fax
MDS2742D
ICRO
C
LOCK
Pin Assignment
MK2742-03, -04, -05, -06
PS2
X2
X1/ICLK
VDD
GND
ACLK
PCLK
AS0
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
PS1
PS0
3.68M
VDD
AS1
GND
13.5M
27M
MK2742
MPEG/Set-Top Clock Source
Audio Clock (in MHz)
Decoding Tables
MK2742-03, -04
AS1
0
0
1
1
AS0
0
1
0
1
ACLK
12.288
16.9344
8.192
11.2896
Processor Clock (in MHz)
MK2742-03, -04, -05, -06
Address \ Version
-03, -05
PS2 PS1 PS0 PCLK
0
0
0
16.67
0
0
1
27
0
1
0
33.33
0
1
1
40
1
0
0
16
1
0
1
40.5
1
1
0
25
1
1
1
20
-04, -06
PCLK
33.33
54
66.66
80
32
81
50
40
MK2742-05, -06
AS1
0
0
1
1
AS0
0
1
0
1
ACLK
11.2896
16.9344
24.576
11.2896
0 = connect directly to ground
1 = connect directly to VDD
16 pin (150 mil) SOIC
Pin Descriptions
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Name
PS2
X2
X1/ICLK
VDD
GND
ACLK
PCLK
AS0
27M
13.5M
GND
AS1
VDD
3.68M
PS0
PS1
Type
I
O
I
P
P
O
O
I
O
O
P
I
P
O
I
I
Description
Processor clock Select 2. Selects processor clock on pin 7 per table above.
Crystal connection. Connect to 27 MHz crystal. Leave unconnected for clock input.
Crystal connection. Connect to 27 MHz crystal or connect to 27 MHz input clock.
Connect to +5V.
Connect to ground.
Audio Clock output. Determined by status of ACS1, ACS0. See table above.
Processor Clock output. Determined by status of PCS2, PCS1, PCS0. See table above.
Audio clock Select 0. Selects audio clock on pin 6 per table above.
27.00 MHz clock output.
13.50 MHz clock output.
Connect to ground.
Audio clock Select 1. Selects audio clock on pin 6 per table above.
Connect to +5V.
3.6864 MHz clock output.
Processor clock Select 0. Selects processor clock on pin 7 per table above.
Processor clock Select 1. Selects processor clock on pin 7 per table above.
Key: I = Input, O = output, P = power supply connection
2
Revision 10277
Printed 10/27/97
MicroClock Division of ICS•1271 Parkmoor Ave.•San Jose•CA•95126•(408)295-9800tel•(408)295-9818fax
MDS2742D
ICRO
C
LOCK
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/ICLK pin only
Input Low Voltage, VIL, X1/ICLK pin only
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
Short Circuit Current
Input Capacitance
Frequency error, ACLK and 3.6864MHz clocks
Frequency error, 24.576 MHz ACLK
Conditions
Referenced to GND
Referenced to GND
Max of 20 seconds
MK2742
MPEG/Set-Top Clock Source
Minimum
Typical
Maximum
7
VDD+0.5
70
260
150
5.5
2.5
2.5
1.5
0.8
Units
V
V
°C
°C
°C
V
V
V
V
V
V
V
V
mA
mA
pF
ppm
ppm
ABSOLUTE MAXIMUM RATINGS (note 1)
-0.5
0
-65
4.5
3.5
2
IOH=-25mA
IOL=25mA
IOH=-8mA
No Load, note 2
Each output
-03, -04 versions
-05, -06 versions
2.4
0.4
VDD-0.4
37
±100
7
0
40
DC 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
%
Absolute Jitter, short term
Variation from mean
200
ps
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 Processor clock at 55MHz, and ACLK at 16.93MHz.
External Components
The MK2742 requires a minimum number of external components for proper operation. Decoupling
capacitors of 0.1µF should be connected between VDD and GND, as close to the MK2742 as possible. A
series termination resistor of 33Ω 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, parallel resonant, 50 ppm 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
-4) x 2. So for a crystal with 16pF load capacitance, two 24pF caps
should be used.
3
Revision 10277
Printed 10/27/97
MicroClock Division of ICS•1271 Parkmoor Ave.•San Jose•CA•95126•(408)295-9800tel•(408)295-9818fax
MDS2742D
ICRO
C
LOCK
Package Outline and Package Dimensions
MK2742
MPEG/Set-Top Clock Source
16 pin SOIC narrow
Symbol
A
b
c
D
E
H
e
h
Q
Inches
Min
Max
0.055 0.070
0.013 0.019
0.007 0.010
0.385 0.400
0.150 0.160
0.225 0.245
.050 BSC
0.016
0.004
0.01
Millimeters
Min
Max
1.397
1.778
0.330
0.483
0.190
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
D
Q
e
b
c
h x 45°
A
Ordering Information
Part/Order Number
MK2742-0xS
MK2742-0xSTR
Marking
MK2742-0xS
MK2742-0xS
Shipping packaging
tubes
tape and reel
Package
16 pin SOIC
16 pin SOIC
Temperature
0-70°C
0-70°C
The -0x signifies the dash number or different version of the MK2742. For instance, if a processor clock of
16.667 MHz is required along with the standard 256X sampling rate frequencies, and parts are needed in
tape and reel, then the order should call for part number MK2742-03STR.
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 10277
Printed 10/27/97
MicroClock Division of ICS•1271 Parkmoor Ave.•San Jose•CA•95126•(408)295-9800tel•(408)295-9818fax
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