FemtoClock NG Crystal-to-LVDS 844N255I Clock Synthesizer Data Sheet General Description Features TH The 844N255I is a 6-output clock synthesizer designed for wireless 4 generation FemtoClock NG technology infrastructure clock applications. The device uses IDTs fourth Selectable 156.25MHz, 125MHz, 100MHz, 50MHz and 25MHz generation FemtoClock NG technology for an optimum of high output clock signals synthesized from a 25MHz reference frequency clock frequency and low phase noise performance, combined with a low power consumption and high power supply noise rejection. The Six differential LVDS clock outputs reference frequency is selectable and the following frequency is Crystal interface designed for a 25MHz crystal supported: 25MHz. The synthesizer generates selectable RMS phase jitter 156.25MHz, using a 25MHz crystal 156.25MHz, 125MHz, 100MHz, 50MHz and 25MHz clock signals. (1MHz - 20MHz): 0.27ps (typical) The device is optimized for very low phase noise and cycle to cycle Internal regulator for optimum noise rejection jitter. The synthesized clock frequency and the phase-noise performance are optimized for driving SRIO 1.3 and 2.0 SerDes LVCMOS interface levels for the frequency select and output enable inputs reference, DSP and host-processor clocks. The device supports a 2.5V voltage supply and is packaged in a small, lead-free (RoHS 6) Full 2.5V supply voltage 48-lead VFQFN package. The extended temperature range supports Lead-free (RoHS 6) 48-lead VFQFN package wireless infrastructure, telecommunication and networking end -40C to 85C ambient operating temperature equipment requirements. Block Diagram XTAL IN 0 25MHz OSC PFD FemtoClock NG 16 QA & VCO XTAL OUT nQA 25MHz 1 Pulldown 20, 25 M QB0 Pulldown 20, 25 nQB0 Pulldown REF CLK 50, 100 QB1 Pulldown REF SEL nQB1 Pullup MSEL 50 Pulldown 100 Pullup QC Pulldown nQC Pulldown Pulldown FSELB Pulldown FSELC Pulldown 5 FSELD QD 2016 Integrated Device Technology, Inc 1 April 28, 2016844N255I Data Sheet Pin Assignment 48 47 46 45 44 43 42 41 40 39 38 37 GND 1 36 GND VDDOA235 VDDA QA334 VDD nQA433 nOEE GNDA532 VDDOE 844N255I nOEA631 QE 48-lead VFQFN 7.0mm x 7.0mm x 0.925mm, package body nOEB730 nQE K Package, Top View 829 VDDOB GNDE QB0928 FSELE nQB0 10 27 VDDOD QB1 11 26 QD nQB1 12 25 nQD 13 14 15 16 17 18 19 20 21 22 23 24 2016 Integrated Device Technology, Inc 2 April 28, 2016 GNDB GND FSELB REF CLK GNDC REF SEL QC XTAL OUT nQC XTAL IN VDDOC VDD nOEC MSEL FSELC VDD VDD VDD FSELD GND nOED GND GNDD GND