ICST MK2745-24S, MK2745-24STR Datasheet
MK2745-24
ICRO
C
LOCK
Description
The MK2745-24 is a low cost, low jitter, high
performance clock synthesizer for DVD and other
MPEG 2 based applications. Using analog PhaseLocked 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.
DVD/MPEG Clock Source
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
Block Diagram
ACS1:0
PCS
27 MHz clock
or crystal
X1
X2
VDD GND
2 3
2
/
Clock Synthesis
and Control
Crystal
Oscillator
Circuitry
• See also the MK2712 for NTSC/PAL clocks
÷8
÷256
Output
Buffer
Output
Buffer
Output
Buffer
Output
Buffer
Output
Buffer
Output
Buffer
PCLK
ACLK
ACLK/8
ACLK/256
27.0 MHz
27.0 MHz
MDS 2745-24 B 1 Revision 100898 Printed 11/16/00
MicroClock Division of ICS•1271 Parkmoor Ave.•San Jose•CA•95126•(408)295-9800tel•(408)295-9818fax
MK2745-24
ICRO
Pin Assignment
MK2745-24
GND ACS1
X2
X1/ICLK
VDD
GND
27M
ACS0
ACLK/8
1
2
3
4
5
6
7
8
16 pin (150 mil) SOIC
16
15
14
13
12
11
10
9
C
LOCK
27M
PCLK
VDD
GND
ACLK
PCS
ACLK/256
DVD/MPEG Clock Source
Audio Clocks Selection Table (in MHz)
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
Processor Clock (MHz)
PCS PCLK
0 40
1 60
0 = connect directly to ground
1 = connect directly to VDD
Pin Descriptions
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.
Key: I = Input, O = output, P = power supply connection
MDS 2745-24 B 2 Revision 100898 Printed 11/16/00
MicroClock Division of ICS•1271 Parkmoor Ave.•San Jose•CA•95126•(408)295-9800tel•(408)295-9818fax
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