W166

W166 Spread Spectrum Frequency Timing Generator Features Maximized EMI suppression using Cypress’s Spread Spectrum technology Generates a spread spectrum copy of the provided input Selectable spreading characteristics Integrated loop filter components Operates with a 3.3V or 5V supply SSON# pin enables frequency spreading Low power CMOS design Available in 8-pin SOIC (Small Outline Integrated Circuit) is greatly reduced. Use of this technology allows systems to pass increasingly difficult EMI testing without resorting to costly shielding or redesign. In a system, not only is EMI reduced in the various clock lines, but also in all signals which are synchronized to the clock. Therefore, the benefits of using this technology increase with the number of address and data lines in the system. The Simplified Block Diagram shows a simple implementation. Table 1. Frequency Spread Selection W166 FS1 0 0 The W166 incorporates the latest advances in PLL spread spectrum frequency synthesizer techniques. By frequency modulating the output with a low-frequency carrier, peak EMI 1 1 FS0 0 1 0 1 Input Frequency (MHz) 50 to 65 50 to 65 50 to 65 50 to 65 Output Frequency (MHz) fIN ±0.625% fIN ±1.25% fIN ±2.5% fIN –3.75% Overview Simplified Block Diagram 3.3V or 5V Pin Configuration Oscillator or Reference Input CLKIN NC GND FS1 1 2 3 4 8 7 6 5 SSON# CLKOUT FS0 VDD W166 W166 Spread Spectrum Output (EMI suppressed) Cypress Semiconductor Corporation 3901 North Firs...