SI570 Datasheet, PDF (1/26 Pages) Silicon Laboratories – ANY-RATE I2C PROGRAMMABLE XO/VCXO

Si570/Si571
PRELIMINARY DATA SHEET
A N Y - R A T E I ²C P R O G R A M M A B L E X O / V C X O
Features
Any-rate programmable output
frequencies from 10 to 945 MHz and
select frequencies to 1.4 GHz
I²C serial interface
3rd generation DSPLL^® with superior
jitter performance
3x better frequency stability than
SAW-based oscillators
Applications
Internal fixed crystal frequency
ensures high reliability and low
aging
Available LVPECL, CMOS,
LVDS, and CML outputs
Industry-standard 5x7 mm
package
Pb-free/RoHS-compliant
1.8, 2.5, or 3.3 V supply
SONET / SDH
xDSL
10 GbE LAN / WAN
Low-jitter clock generation
Optical modules
Clock and data recovery
Description
The Si570 XO/Si571 VCXO utilizes Silicon Laboratories’ advanced DSPLL^®
circuitry to provide a low-jitter clock at any frequency. The Si570/Si571 are
user-programmable to any output frequency from 10 to 945 MHz and select
frequencies to 1400 MHz with <1 ppb resolution. The device is programmed
via an I²C serial interface. Unlike traditional XO/VCXOs where a different
crystal is required for each output frequency, the Si57x uses one fixed-
frequency crystal and a DSPLL clock synthesis IC to provide any-rate
frequency operation. 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.
Functional Block Diagram
V_DD
CLK- CLK+
SDA
Fixed
Frequency
XO
Si571 only
ADC
Any-rate
10-1400 MHz
DSPLL^®Clock
Synthesis
OE
GND
V_C
SCL
Si5602
Ordering Information:
See page 21.
Pin Assignments:
See page 20.
(Top View)
SDA
7
NC ₁
6 VDD
OE 2
5 CLK–
GND 3
4 CLK+
8
SCL
Si570
V_{C 1}
SDA
7
6 VDD
OE 2
5 CLK–
GND 3
4 CLK+
8
SCL
Si571
Rev. 0.3 6/07
Copyright © 2007 by Silicon Laboratories
Si570/Si571
This information applies to a product under development. Its characteristics and specifications are subject to change without notice.