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Low Voltage 2.5V/3.3V Differential LVPECL/HSTL Fanout Buffer

The 8T33FS6111 is a bipolar monolithic differential clock fanout buffer. Designed for most demanding clock distribution systems, the 8T33FS6111 supports various applications that require distribution of precisely aligned differential clock signals. Using SiGe:C technology and a fully differential architecture, the device offers very low skew outputs and superior digital signal characteristics. Target applications for this clock driver is high performance clock distribution in computing, networking and telecommunication systems.
The 8T33FS6111 is designed for low skew clock distribution systems and supports clock frequencies up to 2.7GHz. The device accepts two clock sources. The CLKA input can be driven by LVPECL compatible signals, the CLKB input accepts HSTL or LVPECL compatible signals. The selected input signal is distributed to 10 identical, LVPECL outputs. If VBB is connected to the CLKA input and bypassed to GND by a 10nF capacitor, the 8T33FS6111 can be driven by single-ended LVPECL signals utilizing the VBB bias voltage output.
In order to meet the tight skew specification of the device, both outputs of a differential output pair should be terminated, even if only one output is used. In the case where not all ten outputs are used, the output pairs on the same package side as the parts being used on that side should be terminated. The 8T33FS6111 can be operated from a single 3.3V or 2.5V supply.


  • 1:10 differential clock distribution
  • 28ps typical output skew
  • Fully differential architecture from input to all outputs
  • SiGe:C technology supports near-zero output skew
  • Supports DC to 2.7GHz operation of clock or data signals
  • LVPECL compatible differential clock outputs
  • LVPECL/HSTL compatible differential clock inputs
  • Single 3.3V or 2.5V supply
  • Standard 32-Lead VFQFN package
  • Standard 32-lead LQFP package
  • Standard 32-lead TQFP package with EPAD
  • -40°C to 85°C ambient operating temperature

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)
10LVPECL0.000000 - 3000.0000000.000000 - 3000.0000002LVPECL, HSTL12.5, 3.32.5, 3.3500.1

Product Options

Orderable Part IDPart StatusPkg. CodePkg. TypeLead Count (#)Temp. GradePb (Lead) FreeCarrier TypeSample & Buy
8T33FS6111DXGIActiveDXG32PTQFP32IYesTrayCheck Availability
8T33FS6111DXGI8ActiveDXG32PTQFP32IYesReelCheck Availability
8T33FS6111NLGIActiveNLG32P3VFQFPN32IYesTrayCheck Availability
8T33FS6111NLGI8ActiveNLG32P3VFQFPN32IYesReelCheck Availability
8T33FS6111PFGIActivePRG32TQFP32IYesTrayCheck Availability
8T33FS6111PFGI8ActivePRG32TQFP32IYesReelCheck Availability


Technical Documentation

Title Other Languages Type Format File Size Datesort icon
Datasheets & Errata
8T33FS6111 Datasheet Datasheet PDF 804 KB Jan 6, 2015
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-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-833 Differential Input Self Oscillation Prevention Application Note PDF 94 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# : A1511-01(R1) Add SPEL India as Alternate Assembly Location Product Change Notice PDF 596 KB Jan 28, 2016
show all (4)
PCN# : A1511-01 Add SPEL India as Alternate Assembly Location Product Change Notice PDF 544 KB Nov 13, 2015
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