DATASHEET
DVD/MPEG CLOCK SOURCE MK2745-21
IDT™
DVD/MPEG CLOCK SOURCE 1
MK2745-21 REV E 122109
Description
The MK2745-21 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 MHz fundamental
mode crystal or clock input to produce multiple audio output
clocks, a processor clock, the processor clock divided by
two, 27 MHz, 24.576 MHz, and a selectable audio clock.
The audio clocks are frequency-locked to the 27 MHz using
our patented zero ppm error techniques. This allows audio
and video to track exactly, thereby eliminating the need for
large buffer memory.
IDT manufactures a large variety of DVD, Set-top Box, and
multimedia clock synthesizers for all applications. Consult
IDT to eliminate crystals and oscillators from your board.
Features
• Packaged in a 16-pin narrow (150 mil) SOIC
• Ideal for LuxSonor’s DVD solutions
• 3.3 V upgrade to the MK2744
• Patented zero ppm audio clock error for 256x and 384x
sampling rates
• Selectable audio sampling frequencies support 32, 44.1,
and 48 kHz in most DACs
• 27 MHz fundamental crystal or clock input
• Eight selectable processor frequencies
• Fixed clocks of 27 and 24.576 MHz
• Zero ppm in all clocks
• 25 mA output drive capability at TTL levels
• Advanced, low-power, sub-micron CMOS process
• Operating voltage of 3.0 V to 5.5 V
• See also the MK2712 for NTSC/PAL clocks
NOTE: EOL for non-green parts to occur on 5/13/10
per PDN U-09-01
Block Diagram
27 MHz
Clock Buffer/
Crystal
Ocsillator
PS1:0
24.576 MHz
VDD
GND
Clock
Synthesis and
Control
Circuitry
2
2
Processor Clock
Audio Clock
AS2:0
X1
X2
27 MHz crystal
or clock
3
2
/2 PCLK/2
