SG529
Spread Spectrum Clock Generator
Approved Product
Features
Applications
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Generates Spread Spectrum Clock (SSC)
Programmable Frequencies from 35 to 160 MHz
1.00% and 3.00% Down-Spread Options
Separate Non-Modulated Clock
Pin-Programmable Spread on/off Function
50% Output Clock Duty Cycle
Power-Down Mode for Low Power Dissipation
TTL or CMOS Compatible Outputs
Low Cycle-to-Cycle Jitter of 250 ps-max
External Crystal or Crystal Oscillator Operation
Glitch-Free Switching
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CPU and µC Based Digital Systems
Laser and Inkjet Printers
Digital Copiers
Multifunction Products (MFPs)
Disk Drives
CD-ROM
Automotive
Video and Imaging Applications
Benefits
3 to 5V Power Supply Range
16-Pin Plastic SOIC Package
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12 to 20dB EMI Reduction
Fast Time to Market
Low System and Development Cost
General Description
The IMI SG529 product is a Spread Spectrum Clock Generator (SSCG) designed to reduce the high levels of
Electromagnetic Interference (EMI) found in the high-speed digital systems.
By using a modulated clock as the source for all system clocks and timing signals, the amount of radiated energy
(EMI) throughout the system is greatly reduced. Energy reduction is related to the harmonic frequency, such that
the higher the frequency the greater the energy reduction. The 5th harmonic has greater energy reduction than the
fundamental frequency.
The IMI SG529 produces a wide range of clock frequencies from 35 to 160 MHz which are frequency modulated by
using a Spread Spectrum Clock (SSC) technique to reduce electromagnetic interference (EMI). In addition, a non-
modulated clock output with various standard clock frequencies is also provided for the part of the system which
could be sensitive to a modulated clock. Refer to the Product Selection and Frequency Selection Truth Table for
the available modulated and non-modulated clock frequencies.
When the Spread function is on (SSON), the SG529 can be programmed for 1.00% or 3.00% Down-Spread, or the
Spread function can be turned-off.
The SG529 is designed to be used with a fixed frequency external Crystal or Crystal oscillator. The reference
design frequencies are 14.318 and 48 MHz. with a frequency tolerance of +/- 10%.
The SG529 operates from a 3 to 5V Power supply and 0 to 70°C temperature range, and are available in 16-pin
plastic SOIC package and in die form. Contact IMI for other packaging and Spread Spectrum Clock Generator
(SSCG) products.
INTERNATIONAL MICROCIRCUITS, INC. 525 LOS COCHES ST.,
MILPITAS, CA 95035 408-263-6300, FAX 408-263-6571
http:/www.imicorp.com
Rev. 1.4
3/22/2000
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