IDT8R43002I-01

FemtoClock® Crystal - to - 3.3 V, 2.5 LVPECL Frequencey Synthesizer IDT8R43002I-01 GENERAL DESCRIPTION The IDT8R43002I-01 is a two output LVPECL synthesizer optimized to generate Ethernet reference clock frequencies. Using a 25MHz 18pF parallel resonant crystal, the following frequencies can be generated based on the two frequency select pins (F_SEL[1:0]): 156.25MHz, 125MHz, and 62.5MHz. The IDT8R43002I-01 uses IDT’s FemtoClock® low phase noise VCO technology and can achieve 1ps or lower typical RMS phase jitter, easily meeting Ethernet jitter requirements. The IDT8R43002I-01 is packaged in a small 20-pin TSSOP package. DATA SHEET FEATURES Two 3.3V or 2.5V LVPECL outputs Selectable crystal oscillator interface or LVCMOS/LVTTL single-ended input Supports the following output frequencies: 156.25MHz, 125MHz and 62.5MHz VCO range: 560MHz - 680MHz RMS phase jitter @ 156.25MHz, using a 25MHz crystal (1.875MHz-20MHz): 0.55ps (typical) Output skew: 30ps (maximum) Supply Voltage Modes Core/Outputs 3.3/3.3 2.5/2.5 -40°C to 85°C ambient operating temperature Available in lead-free RoHS-compliant packages TABLE 1. FREQUENCY SELECT FUNCTION TABLE F_SEL1 0 Inputs F_SEL0 M Divider Value 0 25 N Divider Value 4 Output Frequency (25MHz Ref.) 156.25 (default) 0 1 25 5 125 1 0 25 10 62.5 1 1 25 5 125 BLOCK DIAGRAM F_SEL[1:0] 2 nPLL_SEL REF_CLK XTAL_IN XTAL_OUT nXTAL_SEL 1 OSC 0 Phase Detector VCO 625MHz (w/25MHz Reference) 1 0 F_SEL[1:0] 0 0 ÷4 (d...