843031AGLFT

FemtoClock® Crystal-to-3.3V LVPECL Clock Generator ICS843031 DATA SHEET GENERAL DESCRIPTION FEATURES The 843031 is a 1 Gigabit Ethernet Clock Generator. The 843031 can synthesize 1 Gigabit Ethernet, SONET, or Serial ATA reference clock frequencies with the appropriate choice of crystal and output divider. The 843031 has excellent phase jitter performance and is packaged in a small 8-pin TSSOP, making it ideal for use in systems with limited board space. • One differential 3.3V LVPECL output • Crystal oscillator interface designed for 18pF parallel resonant crystals • Output frequency range: 290MHz - 350MHz • VCO frequency range: 580MHz - 700MHz • RMS phase jitter @312.5MHz (1.875MHz - 20MHz): 0.475ps (typical) RMS phase jitter @318.75MHz (1.875MHz - 20MHz): 0.475ps (typical) • 3.3V operating supply • 0°C to 70°C ambient operating temperature • Available in lead-free (RoHS 6) package • For functional replacement part use 843031i-01 FREQUENCY TABLE Inputs M/N Ratio (Multiplier) Output Frequency (MHz) 25.92 12 311.04 26.04166 12 312.5 26.5625 12 318.75 Crystal Frequency (MHz) BLOCK DIAGRAM PIN ASSIGNMENT XTAL_IN OSC XTAL-OUT Phase Detector VCO ÷2 Q0 1 2 3 4 8 7 6 5 Q0 nQ0 VCC PWR_DN 843031 8-Lead TSSOP 4.40mm x 3.0mm x 0.925mm package body G Package Top View ÷24 (fixed) PWR_DN 843031 REVISION A 11/5/15 nQ0 VCC XTAL_OUT XTAL_IN VEE 1 FEMTOCLOCK® CRYSTAL-TO-3.3V LVPECL CLOCK GENERATOR 843031 Data Sheet TABLE 1. PIN DESCRIPTIONS Number Name Type Description 1, 6 VCC Power Core supply pin. 2, 3 XTAL_OUT, XTAL_IN Input Crystal oscillator interface. XTAL_IN is the input, XTAL_OUT is the output. 4 VEE Power Negative supply pin. 5 PWR_DN Input 7, 8 nQ0, Q0 Output Pullup Output state control input. High impedance when LOW (oscillator stops). LVCMOS/LVTTL interface levels. Differential clock outputs. LVPECL interface levels. NOTE: Pullup refers to internal input resistors. See Table 2, Pin Characterristics, for typical values. TABLE 2. PIN CHARACTERISTICS Symbol Parameter CIN Input Capacitance 4 pF RPULLUP Input Pullup Resistor 51 kΩ 843031 REVISION A 11/5/15 Test Conditions 2 Minimum Typical Maximum Units FEMTOCLOCK® CRYSTAL-TO-3.3V LVPECL CLOCK GENERATOR 843031 Data Sheet ABSOLUTE MAXIMUM RATINGS Supply Voltage, VCC 4.6V Inputs, VI -0.5V to VCC + 0.5V Outputs, IO Continuous Current Surge Current 50mA 100mA Package Thermal Impedance, θJA 101.7°C/W (0 mps) Storage Temperature, TSTG -65°C to 150°C NOTE: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These ratings are stress specifications only. Functional operation of product at these conditions or any conditions beyond those listed in the DC Characteristics or AC Characteristics is not implied. Exposure to absolute maximum rating conditions for extended periods may affect product reliability. TABLE 3A. POWER SUPPLY DC CHARACTERISTICS, VCC = 3.3V±5%, TA=0°C TO 70°C Symbol Parameter VCC Core Supply Voltage IEE Test Conditions Power Supply Current Minimum Typical Maximum 3.135 3.3 Units 3.465 V PWR_DN = 1 105 mA PWR_DN = 0