Description
The Si554 quad-frequency VCXO utilizes Skyworks Solutions’ advanced
DSPLL® circuitry to provide a very low jitter clock for all output frequencies.
The Si554 is available with any-rate output frequency from 10 to 945 MHz
and selected frequencies to 1400 MHz. Unlike traditional VCXOs, where a
different crystal is required for each output frequency, the Si554 uses one
fixed crystal frequency to provide a wide range of output frequencies. This
IC-based approach allows the crystal resonator to provide exceptional
frequency stability and reliability. 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 Si554 IC-based VCXO is factory-configurable for a wide
variety of user specifications including frequency, supply voltage, output
format, tuning slope, and temperature stability. Specific configurations are
factory-programmed at time of shipment, thereby eliminating the long lead
times associated with custom oscillators.

Features
 Available with any-rate output
frequencies from 10–945 MHz and
selected frequencies to 1.4 GHz
 Four selectable output frequencies
 3rd generation DSPLL® with superior
jitter performance
 3x better frequency stability than
SAW-based oscillators
 Internal fixed crystal frequency
ensures high reliability and low
aging
 Available CMOS, LVPECL,
LVDS, and CML outputs
 3.3, 2.5, and 1.8 V supply options
 Industry-standard 5 x 7 mm
package and pinout
 Pb-free/RoHS-compliant

Applications
 SONET/SDH
 xDSL
 10 GbE LAN / WAN
 Low jitter clock generation
 Optical modules
 Clock and data recovery