Si550
PRELIMINARY DATA SHEET
VOLTAGE-CONTROLLED CRYSTAL OSCILLATOR (VCXO)
(10 MHZ TO 1.4 GHZ)
Features
®
Available with any-rate output
frequencies from 10 MHz to 945 MHz
and selected frequencies to 1.4 GHz
Industry-standard 7x5 mm package
Available CMOS, LVPECL, & CML
outputs
3rd generation DSPLL with
superior jitter performance
Internal fixed crystal frequency
ensures high reliability and low
aging
Si5602
Lead-free/RoHS-compliant
3x better frequency stability than
SAW based oscillators
Applications
Ordering Information:
SONET / SDH
xDSL
10 GbE LAN / WAN
Low-jitter clock generation
Optical modules
Clock and data recovery
See page 7.
Description
®
The Si550 VCXO utilizes Silicon Laboratories’ advanced DSPLL circuitry
to provide a low-jitter clock at high frequencies. The Si550 is available with
any-rate output frequency from 10 to 945 MHz and selected frequencies to
1400 MHz. Unlike a traditional VCXO, the crystal frequency inside the Si550
is fixed for a wide range of output frequencies. The control voltage is
digitized and used as a numerical input to the DSPLL clock synthesis
engine. This IC-based approach eliminates the varactor and its associated
noise and non-linear performance drawbacks, allowing the crystal resonator
to be optimized for superior frequency stability, reliability, and mechanical
integrity. In addition, DSPLL clock synthesis provides superior supply noise
rejection, simplifying the task of generating low-jitter clocks in noisy
environments typically found in communication systems. The Si550 IC-
based VCXO is factory configurable for a wide variety of user specifications
including frequency, supply voltage, output, and tuning slope. Specific
configurations are factory programmed into the Si550 at time of shipment,
thereby eliminating the long lead times associated with custom oscillators.
Functional Block Diagram
CLK- CLK+
VDD
Any-rate
10-1400 MHz
DSPLL™
Clock
Fixed
Frequency
XO
Synthesis
ADC
Vc
OE
GND
Preliminary Rev. 0.2 8/05
Copyright © 2005 by Silicon Laboratories
Si550
This information applies to a product under development. Its characteristics and specifications are subject to change without notice.