IMISG509 Datasheet | International Microcircuits

FEATURES þ þ þ þ þ þ þ þ þ þ þ Generates CPU clock signals for microprocessor systems Reduces measured EMI by 10 d B nominal 4V to 6V operating supply range Supports CPUs from all major manufacturers. Wide range of selectable output frequencies including 60, 50, 48, 40, 33.3, 16.7 Single, low-cost frequency crystal used as reference PRODUCT DESCRIPTION The IMISG509 is a spectrum spread clock generator specially designed for personal puters, laser printers and other digital systems. IMISG509 uses a patented concept to generate popular clock frequencies that are intentionally broadbanded to reduce electromagnetic interference. The radiated emissions, associated with either the clock, harmonics or any signals derived from the clock, nominally reduced by 10 d B and could significantly reduce the cost of plying with the regulatory requirements. PRCLK is the broadbanded output and can be programmed by the PRCLK Frequency Selection Table on Page 2. A single, low cost external crystal is required as reference frequency for the synthesizer. The output modulation function can be disabled when the SSON pin is high. Glitch-free switching 50% duty cycle TTL or CMOS patible outputs with 6 m A drive capability Low, short and long-term jitter 16 pin P-DIP and 16 Pin SOIC (300 mil body) package options CONNECTION DIAGRAM VDD OSCin OSCout VSS MPSEL AVDD S0 S1 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 S3 VDD MPCLK VSS PRCLK AVSS LF1 SSON BLOCK DIAGRAM 3 44.2 MHz 2 REF /4 OR /12 14 MPCLK MPSEL 5 10 7 8 16 9 SPECTRUM SPREAD CLOCK GEN LF S0 S1 S3 SSON /2 12 PRCLK APPLICATIONS IMISG509 eliminates the need for multiple oscillators and generates the CPU clock signals for personal puters, laser printers and other digital systems. Supports CPUs from all major manufacturers. INTERNATIONAL MICROCIRCUITS, INC. 525 LOS COCHES ST. MILPITAS, CA 95035 TEL: 408-263-6300 FAX 408-263-6571 Page 1 of 7 .. April 1996 REDUCED EMI CLOCK CHIP CMOS LSI SPECTRUM SPREAD CLOCK GENERATOR PIN...