M908-01

Integrated Circuit Systems, Inc. Preliminary Information M908-01 VCSO BASED GBE CLOCK GENERATOR PIN ASSIGNMENT (9 x 9 mm SMT) XTAL_1 / REF_IN GND nFOUT5 FOUT5 nFOUT4 FOUT4 nFOUT3 FOUT3 VCC XTAL_2 FOUT6 nFOUT6 FOUT7 nFOUT7 VCC DNC DNC DNC 27 26 25 24 23 22 21 20 19 GENERAL DESCRIPTION The M908-01 is a PLL (Phase Locked Loop) based clock generator that uses an internal VCSO (Voltage Controlled SAW Oscillator) to produce a very low jitter output clock. It is ideal for Gigabit Ethernet. An output clock frequency of 156.25MHz (with the M908-01-156.2500) is provided from eight LVPECL clock output pairs. The accuracy of the output frequency is assured by the internal PLL that phase-locks the internal VCSO to the reference input frequency (25MHz for the M908-01-156.2500). The input reference can either be an external crystal, utilizing the internal crystal oscillator, or a stable external clock source such as a packaged crystal oscillator. 28 29 30 31 32 33 34 35 36 M908-01 (Top View) 18 17 16 15 14 13 12 11 10 nFOUT2 FOUT2 nFOUT1 FOUT1 GND nFOUT0 FOUT0 VCC GND FEATURES ◆ 156.25MHz output clock frequency (M908-01-156.2500) ◆ Eight identical LVPECL output pairs ◆ Jitter 0.7ps RMS (over 12kHz-20MHz) ◆ Ideal for Gigabit Ethernet clock reference ◆ Output-to-output skew < 100ps ◆ External XTAL or LVCMOS reference input ◆ Integrated SAW (surface acoustic wave) delay line ◆ Single 3.3V power supply ◆ Small 9 x 9 mm SMT (surface mount) package http://www.DataSheet4U.net/ Figure 1: ...