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85311I - Block Diagram
85311I - Pinout


Low Skew,1-to-2,Differential-to-LVPECL/ECL Fanout Buffer

The 85311I is a low skew, high performance 1-to-2 Differential-to-2.5V/3.3V ECL/LVPECL Fanout Buffer and a member of the HiPerClockS™ family of High Performance Clock Solutions from IDT. The CLK, nCLK pair can accept most standard differential input levels.The 85311I is characterized to operate from either a 2.5V or a 3.3V power supply. Guaranteed output and part-to-part skew characteristics make the 85311I ideal for those clock distribution applications demanding well defined performance and repeatability.


  • Two differential 2.5V/3.3V LVPECL / ECL outputs
  • One CLK, nCLK input pair
  • CLK, nCLK pair can accept the following differential input levels: LVDS, LVPECL, LVHSTL, SSTLHCSL
  • Maximum output frequency: 1GHz
  • Translates any single ended input signal to 3.3V LVPECL levels with resistor bias on nCLK input
  • Output skew: 20ps (maximum)
  • Part-to-part skew: 350ps (maximum)
  • Propagation delay: 2.1ns (maximum)
  • Additive phase jitter, RMS: 0.14ps (typical), 3.3V
  • LVPECL mode operating voltage supply range: VCC = 2.375V to 3.465V, VEE = 0V
  • ECL mode operating voltage supply range: VCC = 0V, VEE = -2.375V to -3.465V
  • -40°C to 85°C ambient operating temperature
  • Available in lead-free (RoHS 6) package

Product Specification

Outputs (#)Output TypeOutput Freq Range (MHz)Input Freq (MHz)Inputs (#)Input TypeOutput Banks (#)Core Voltage (V)Output Voltage (V)Divider ValueOutput Skew (ps)Additive Phase Jitter Typ RMS (ps)
2LVPECL0.000000 - 1000.0000000.000000 - 1000.0000001HSTL, LVDS, LVPECL, SSTL, HCSL12.5, 3.32.5, 3.3200.14

Product Options

Orderable Part IDPart StatusPkg. CodePkg. TypeLead Count (#)Temp. GradePb (Lead) FreeCarrier TypeSample & Buy
85311AMILFActiveDCG8SOIC8IYesTubeCheck Availability
85311AMILFTActiveDCG8SOIC8IYesReelCheck Availability


Technical Documentation

Title Other Languages Type Format File Size Datesort icon
Datasheets & Errata
85311I Final Data Sheet Datasheet PDF 418 KB Mar 21, 2016
Apps Notes & White Papers
AN-828 Termination - LVPECL Application Note PDF 229 KB Jul 5, 2016
AN-844 Termination - AC Coupling Clock Receivers Application Note PDF 82 KB May 13, 2014
AN-842 Thermal Considerations in Package Design and Selection Application Note PDF 403 KB May 12, 2014
show all (11)
AN-840 Jitter Specifications for Timing Signals Application Note PDF 349 KB May 8, 2014
AN-833 Differential Input Self Oscillation Prevention Application Note PDF 94 KB May 6, 2014
AN-836 Differential Input to Accept Single-ended Levels Application Note PDF 37 KB May 6, 2014
AN-835 Differential Input with VCMR being VIH Referenced Application Note PDF 77 KB May 6, 2014
AN-834 Hot-Swap Recommendations Application Note PDF 67 KB May 6, 2014
AN-827 Application Relevance of Clock Jitter Application Note PDF 1.06 MB Apr 24, 2014
AN-815 Understanding Jitter Units Application Note PDF 476 KB Apr 24, 2014
AN-805 Recommended Ferrite Beads Application Note PDF 38 KB Jan 15, 2014
PCN# : A1602-01(R1) Add Greatek Taiwan as Alternate Assembly Product Change Notice PDF 611 KB Apr 14, 2016
PCN# : A1602-01 Add Greatek Taiwan as Alternate Assembly Product Change Notice PDF 611 KB Feb 15, 2016
PCN# : TB1504-01R1 Qty per Reel Standardization for Selective Packages Product Change Notice PDF 95 KB Oct 22, 2015
show all (6)
PCN# : A1509-03 Gold to Copper wire Product Change Notice PDF 31 KB Oct 15, 2015
PCN# : TB1504-01 Qty per Reel Standardization for Selective Packages Product Change Notice PDF 50 KB Jul 21, 2015
PCN# : TB1303-02 Change of Tape & Reel Packing Method for Selective Products Product Change Notice PDF 361 KB Mar 24, 2013
IDT Clock Generation Overview 日本語 Overview PDF 1.83 MB Apr 28, 2016
IDT Clock Distribution Overview 日本語 Overview PDF 3.79 MB Apr 25, 2016
IDT Fanout Buffers Product Overview Product Brief PDF 739 KB Feb 17, 2015
show all (4)
High-Performance, Low-Phase Noise Clocks Buffers product brief Product Brief PDF 378 KB Aug 14, 2012

Software & Tools

Title Type Format File Size Datesort icon
85311I IBIS Model Model - IBIS ZIP 55 KB Nov 21, 2009