ACS1790T

SCL SDA A0 FBCLK A1 VDDD2 ADVANCED COMMUNICATIONS PRODUCT GROUP Introduction The ACS1790T is a high-performance, low phase noise, programmable frequency synthesizer with ultra-fine dynamic output frequency control. It can be used as a companion to a compatible ToPSync™ device to generate outputs locked to an external reference source or standalone for standard frequency generation for common applications. The circuit includes an integrated VCO, loop filter, phase-and-frequency detector and output dividers. The default power-up mode is definable by pin settings and once operational the ACS1790T is fully-programmable via an I2C interface. The ACS1790T requires only a low-speed external clock input for operation. When used in conjunction with a compatible ToPSync® device in a Synchronous Ethernet system the ACS1790T allows the Ethernet transmit clocks to be derived initially from the local reference oscillator and subsequently frequency-locked to an external reference source once the system is fully configured, simplifying system design and reducing component count and BOM cost. Pin Diagram LD OEB MODE IC VSSF VDDF 24 19 RESETB 1 OSCFSEL0 CLK OSCFSEL1 VDDD VSSD 6 ACS1790T 18 VDDA OUT1P OUT1N VSSA VSSD2 13 OUT2 7 12 ACS1790T PLL Frequency Synthesizer with Integrated VCO FINAL DATASHEET Features  Optimised for Synchronous Ethernet, SONET and SDH operation  Meets RMS jitter requirements of Gigabit Ethernet, 10 Gigabit Ethernet and OC-48 / STM16  Default options for 25 MH...