MAX3672 Datasheet, PDF (1/12 Pages) Maxim Integrated Products – Low-Jitter 155MHz/622MHz Clock Generator

19-2697; Rev 0; 12/02
Low-Jitter 155MHz/622MHz Clock Generator
General Description
The MAX3672 is a low-jitter 155MHz/622MHz reference
clock generator IC designed for system clock distribution
and frequency synchronization in OC-48 and OC-192
SONET/SDH and WDM transmission systems. The
MAX3672 integrates a phase/frequency detector, an
operational amplifier (op amp), prescaler dividers, and
input/output buffers. Using an external VCO, the
MAX3672 can be configured easily as a phase-lock loop
with bandwidth programmable from 30Hz to 10kHz.
The MAX3672 operates from a single +3.3V or +5.0V
supply and dissipates 150mW (typ) at 3.3V. The operat-
ing temperature range is -40°C to +85°C.
Applications
OC-12 to OC-192 SONET/WDM Transport
Systems
Clock Jitter Clean-Up and Frequency
Synchronization
Frequency Conversion
System Clock Distribution
Features
o Single +3.3V or +5.0V Supply
o Power Dissipation: 150mW at +3.3V Supply
o External VCO Center Frequencies (f_VCO): 155MHz
to 700MHz
o Reference Clock Frequencies: f_VCO, f_VCO/2,
f_VCO/4, f_VCO/8, f_VCO/32
o Main Clock Output Frequency: f_VCO
o Optional Output Clock Frequencies: f_VCO, f_VCO/2,
f_VCO/4, f_VCO/8
o Low Intrinsic Jitter: <0.4ps_RMS
o Loss-of-Lock Indicator
o PECL Clock Output Interface
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
MAX3672E/D
-40°C to +85°C
Dice*
*Dice are designed to operate from -40° to +85°C, but are test-
ed and guaranteed at T_A = +25° only.
Typical Application Circuit
+3.3V _142Ω
VCO
K_VCO = 25kHz/V
155MHz
142Ω
155MHz
100Ω
+3.3V
REFCLK+
REFCLK-
VCOIN+
VCCD
VCOIN- ^MAX3672
0.01µF
332Ω
4700pF
4700pF
REPRESENTS A
CONTROLLED-IMPEDANCE
TRANSMISSION LINE.
500kΩ
500kΩ
VC
OPAMP-
OPAMP+
VFILTER
1000pF
POLAR
142Ω
MOUT+
MOUT-
142Ω
RSEL
VSEL
N.C.
NSEL1
N.C.
NSEL2
GSEL
GND
3.3V
SETUP FOR 10kHz LOOP
BANDWIDTH
MAX3892
16:1
SERIALIZER
________________________________________________________________ Maxim Integrated Products 1
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