FS781

www.DataSheet4U.com FS781/82/84 Low EMI Spectrum Spread Clock Features Spread Spectrum clock generator (SSCG) with 1×, 2×, and 4× outputs 6- to 82-MHz operating frequency range Modulates external clocks including crystals, crystal oscillators, or ceramic resonators Programmable modulation with simple R-C external loop filter (LF) Center spread modulation 3V-5V power supply TTL-/CMOS-compatible outputs Low short-term jitter Low-power Dissipation — 3.3 VDC = 37 mW – typical — 5.0 VDC = 115 mW – typical Available in 8-pin SOIC and TSSOP packages Functional Description The Cypress FS781/82/84 are Spread Spectrum clock generator ICs (SSCG) designed for the purpose of reducing electromagnetic interference (EMI) found in today’s high-speed digital systems. The FS781/82/84 SSCG clocks use a Cypress-proprietary technology to modulate the input clock frequency, XIN, by modulating the frequency of the digital clock. By modulating the reference clock the measured EMI at the fundamental and harmonic frequencies of FSOUT is greatly reduced. This reduction in radiated energy can significantly reduce the cost of complying with regulatory requirements without degrading digital waveforms. The Cypress FS781/82/84 clocks are very simple and versatile devices to use. By programming the two range select lines, S0 and S1, any frequency from 6- to 82-MHz operating range can be selected. The FS781/2/4 are designed to operate over a very wide range of input frequencies and provi...