Description

The AD9577 provides a multioutput clock generator function,along with two on-chip phase-locked loop cores, PLL1 and PLL2,optimized for network clocking applications. The PLL designsare based on the Analog Devices, Inc., proven portfolio of highperformance, low jitter frequency synthesizers to maximizenetwork performance. The PLLs have I2C programmable outputfrequencies and formats. The fractional-N PLL can supportspread spectrum clocking for reduced EMI radiated peak power.Both PLLs can support frequency margining. Other applicationswith demanding phase noise and jitter requirements can benefitfrom this part.The first integer-N PLL section (PLL1) consists of a low noise phasefrequency detector (PFD), a precision charge pump (CP), a lowphase noise voltage controlled oscillator (VCO), a programmablefeedback divider, and two independently programmable outputdividers. By connecting an external crystal or applying a referenceclock to the REFCLK pin, frequencies of up to 637.5 MHz canbe synchronized to the input reference. Each output divider andfeedback divider ratio is I2C programmed for the requiredoutput rates.A second fractional-N PLL (PLL2) with a programmable modulusallows VCO frequencies that are fractional multiples of thereference frequency to be synthesized. Each output dividerand feedback divider ratio can be programmed for the requiredoutput rates, up to 637.5 MHz. This fractional-N PLL can alsooperate in integer-N mode for the lowest jitter.Up to four differential output clock signals can be configuredas either LVPECL or LVDS signaling formats. Alternatively,the outputs can be configured for up to eight CMOS outputs.Combinations of these formats are supported. No external loopfilter components are required, thus conserving valuable designtime and board space. The AD9577 is available in a 40-lead, 6 mm ?6 mm LFCSP package and can operate from a single 3.3 V supply.The operating temperature range is ?40?C to +85?C.Applications Low jitter, low phase noise multioutput clock generator for data communications applications including Ethernet, Fibre Channel, SONET, SDH, PCI-e, SATA, PTN, OTN, ADC/DAC, and digital video Spread spectrum clocking

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Part number: AD9577-EVALZ

More details from Analog Devices Inc.