SG521

Approved Product Features Generates Spread Spectrum Clock (SSC) Programmable Frequencies from 10 to 120 MHz 1.25% and 3.25% 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 Clock or Crystal Oscillator Operation Glitch-Free Switching 3 to 5V Operation Supply Range 16-Pin Plastic SOIC Package SG521/22/24/28 Spread Spectrum Clock Generator Applications 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 12 to 20dB EMI Reduction Fast Time to Market Low System and Development Cost General Description IMI SG521/22/24/28 products are Spread Spectrum Clock Generators designed to reduce the high levels of Electromagnetic Interference (EMI) found in 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 SG521/2/4/8 products produce a wide range of clock frequencies from 10 to 120 MHz, which are f...