M685

Integrated Circuit Systems, Inc. Preliminary Information M685 nFOUT DUAL SAW, SELECTABLE FREQUENCY VCSO PIN ASSIGNMENT (5 x 7.5mm SMT) FOUT VCC GENERAL DESCRIPTION The M685 is a dual SAW, selectable frequency VCSO frequency source for low-jitter clock generation. An integrated SAW (surface acoustic wave) delay line implements the high-Q VCO (voltage controlled oscillator) function, which results in low output phase noise and very low jitter. The M685-01 is available in a range of center frequencies from 125 to 175 MHz. The M685-02 provides 500 to 700 MHz. Guaranteed minimum pull-range of ±120 ppm meets GbE requirements. (It also fully satisfies ±50 ppm minimum pull-range specification commonly required.) Industrystandard Kvco (VCO Gain) provides full replacement compatibility. The M685 is well suited for phase-locked loop implementations, clock and data recovery circuits, and other timing applications in telecom and optical fiber networking systems (e.g., OC-48). 6 5 M685 M680 ( To p Vi ew) 1 2 VIN F_SEL Figure 1: Pin Assignment Sample of Available Output Frequencies VCSO Center Frequencies1 (MHz) 155.5200, 167.3316 156.2500, 161.1328 622.0800, 669.3266 625.0000, 644.5313 Applications SONET/SDH, SONET/SDH FEC Gigabit Ethernet, GbE FEC SONET/SDH, SONET/SDH FEC Gigabit Ethernet, GbE FEC FEATURES ◆ Two integrated SAW devices and selectable output frequency; supports multi-rate optical interfaces ◆ M685-01 output frequencies from 125 to 175 MHz M685-02 output freque...