I C R O
C
LOC K
Description
The MK2772-01 is a low cost, low jitter, high
performance VCXO and clock synthesizer for set-
top boxes. The on-chip Voltage Controlled
Crystal Oscillator accepts a 0 to 3V input voltage
to cause the output clocks to vary by ±100 ppm.
Using MicroClock’s patented VCXO and analog
Phase-Locked Loop (PLL) techniques, the device
uses an inexpensive 13.5 MHz crystal input to
produce multiple output clocks. All clocks are
frequency locked to the 27.00MHz output (and to
each other) with zero ppm error. The MK2772
includes a glitch-free multiplexer to switch input
sources during operation.
MicroClock manufactures the largest variety of
Set-Top Box and multimedia clock synthesizers
for all applications. Consult MicroClock to
eliminate VCXOs, crystals and oscillators from
your board.
MK2772-01
VCXO and Set-Top Clock Source
Features
• Packaged in 20 pin SOIC
• Uses an inexpensive 13.5 MHz crystal
• On-chip VCXO (patented) with pull range
of 200ppm (minimum)
• Ability to switch input sources “on-the-fly”
• VCXO tuning voltage of 0 to 3V
• Zero ppm synthesis error (patented) in all
clocks. All exactly track 27MHz VCXO
• All clocks are frequency locked. All will vary the
same amount (in ppm) as the VCXO
• Selectable Audio clock for 256x, 384x, and 512x.
• 25mA output drive capability at TTL levels
• Advanced, low power, sub-micron CMOS process
• 5V operating voltage
Block Diagram
VDD GND
3
3
2
Clock
Synthesis
Circuitry
Output
Buffer
Output
Buffer
Output
Buffer
Output
Buffer
Voltage Controlled
Crystal Oscillator
and x2 PLL
ACS1:0
Audio Clock
16.6667 MHz
11.0592 MHz
INMUXSEL
EXTCLKIN
VIN
13.5 MHz
pullable
crystal
X1
3.6864 MHz
3
X2
deglitched
mux
Output
Buffers
27.000 MHz
1
Revision 012098
Printed 11/16/00
Integrated Circuit Systems, Inc.•525 Race Street•San Jose•CA•95126•(408)295-9800tel•www.icst.com
MDS 2772-01 B
ICS [ INTEGRATED CIRCUIT SYSTEMS ]
