MK2059-01
VCXO-Based Frame Clock Frequency Translator
Description
The MK2059-01 is a VCXO (Voltage Controlled Crystal
Oscillator) based clock generator that produces
common telecommunications reference frequencies.
The output clock is phase locked to an 8kHz (frame
rate) input reference clock. The MK2059-01 also
provides jitter attenuation. Included in the selection of
output frequencies are these common system clocks:
1.544 MHz (T1)
19.44 MHz (OC-3)
2.048 (E1)
16.384 MHz (8x E1)
Features
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Generates T1, E1, OC-3 and other common telecom
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clock frequencies from an 8kHz frame clock
Configurable jitter attenuation characterisitics,
excellent for use as a Stratum source de-jitter circuit
2:1 Input MUX for input reference clocks
VCXO-based clock generation offers very low jitter
and phase noise generation
Output clock is phase and frequency locked to the
selected input reference clock
Fixed input to output phase relationship
+115ppm minimum crystal frequency pullability
range, using recommended crystal
Industrial temperature range
Low power CMOS technology
20 pin SOIC package
Single 3.3V power supply
This monolithic IC, combined with an external
inexpensive quartz crystal, can be used to replace a
more costly hybrid VCXO retiming module. Through
selection of external loop filter components, the PLL
loop bandwidth and damping factor can be tailored to
meet input clock jitter attenuation requirements. A loop
bandwidth down to the Hz range is possible.
Block Diagram
P ullable x tal
VD D
IS E T
X1
X2
VDD
3
8kH z R ef In p ut
8kH z R ef In p ut
IC L K 2
IC L K 1
1
0
P h ase
D etecto r
C harg e
P um p
V C XO
O u tpu t
D ivid er
CLK
ISE L
F eedb ack
D ivid er
S EL 2:0
3
CHGP
VIN
GND
4
MDS 2059-01 B
1
Revision 071001
Integrated Circuit Systems, Inc.
q
525 Race Street, San Jose, CA 95126
q
tel (408) 295-9800
q
www.icst.com