1-to-8 Differential to Universal Output Clock Divider/Fanout Buffer

NOTICE - The following device(s) are recommended alternatives:

The 8T79S818I-08 is a high performance, 1-to-8, differential input to universal output clock divider and fanout buffer. The device is designed for frequency-division and signal fanout of high-frequency clock signals in applications requiring four different output frequencies generated simultaneously. Each bank of two outputs has a selectable divider value of ÷1 through ÷6 and ÷8. The 8T79S818I-08 is optimized for 3.3 V and 2.5 V supply voltages and a temperature range of -40°C to 85°C. The device is packaged in a space-saving 32 lead VFQFN package.


  • Four banks of two low skew outputs 
  • Selectable bank output divider values: ÷1 through ÷6 and ÷8
  • One differential PCLK, nPCLK input
  • PCLK, nPCLK input pair can accept the following differential input levels: LVPECL, LVDS or CML levels
  • Maximum input frequency: 1.5GHz 
  • LVCMOS control inputs
  • QXx ÷1 edge aligned to QXx ÷n edge
  • Individual output divider control via serial interface
  • Individual output enable/disable control via serial interface
  • Individual output type control, LVDS or LVPECL, via serial interface
  • 2.375 V to 3.465 V supply voltage operation
  • -40°C to 85°C ambient operating temperature
  • Lead-free (RoHS 6) packaging
  • Supported by IDT's Timing Commander Software

Product Options

Orderable Part ID Part Status Pkg. Code Pkg. Type Lead Count (#) Temp. Grade Pb (Lead) Free Carrier Type Buy Sample
8T79S818A-08NLGI Obsolete NLG32P1 VFQFPN 32 I Yes Tray Availability
8T79S818A-08NLGI8 Obsolete NLG32P1 VFQFPN 32 I Yes Reel Availability

Technical Documentation

Title Other Languages Type Format File Size Date
Datasheets & Errata
IDT8T79S818I-08 Datasheet Datasheet PDF 481 KB Jul 14, 2013
User Guides & Manuals
Timing Commander Installation Guide Guide PDF 497 KB Oct 6, 2013
Application Notes & White Papers
AN-828 Termination - LVPECL Application Note PDF 229 KB Jul 5, 2016
AN-846 Termination - LVDS Application Note PDF 50 KB May 12, 2014
AN-844 Termination - AC Coupling Clock Receivers Application Note PDF 82 KB May 12, 2014
AN-842 Thermal Considerations in Package Design and Selection Application Note PDF 403 KB May 11, 2014
AN-835 Differential Input with VCMR being VIH Referenced Application Note PDF 77 KB May 10, 2014
AN-840 Jitter Specifications for Timing Signals Application Note PDF 349 KB May 7, 2014
AN-834 Hot-Swap Recommendations Application Note PDF 67 KB May 5, 2014
AN-833 Differential Input Self Oscillation Prevention Application Note PDF 94 KB May 5, 2014
AN-836 Differential Input to Accept Single-ended Levels Application Note PDF 37 KB May 5, 2014
AN-827 Application Relevance of Clock Jitter Application Note PDF 1.06 MB Apr 23, 2014
AN-815 Understanding Jitter Units Application Note PDF 476 KB Apr 23, 2014
AN-805 Recommended Ferrite Beads Application Note PDF 38 KB Jan 14, 2014
PDN# : CQ-17-04(R1) Product Discontinuance Notice Product Discontinuation Notice PDF 606 KB Nov 29, 2017
PDN# : CQ-17-04 Product Discontinuance Notice Product Discontinuation Notice PDF 599 KB Aug 24, 2017
PCN# : A1611-02 Add JCET China as Alternate Assembly and Change of Material Set at Alternate Assembly Location Product Change Notice PDF 583 KB Dec 19, 2016
PCN# : A1511-01(R1) Add SPEL India as Alternate Assembly Location Product Change Notice PDF 596 KB Jan 27, 2016
PCN# : A1511-01 Add SPEL India as Alternate Assembly Location Product Change Notice PDF 544 KB Nov 12, 2015
The IDT Consumer Products Advantage Overview PDF 4.01 MB Jun 30, 2017
The IDT Automotive Advantage 日本語 Overview PDF 3.55 MB May 26, 2017
The IDT Communications Products Advantage Overview PDF 2.54 MB Feb 13, 2017
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 24, 2016
IDT Fanout Buffers Product Overview Product Brief PDF 739 KB Feb 16, 2015
8T79S818i-08 Timing Commander File Engineering TCP 896 KB Oct 6, 2013
High-Performance, Low-Phase Noise Clocks Buffers product brief Product Brief PDF 378 KB Aug 13, 2012

Software & Tools

Title Other Languages Type Format File Size Date
Timing Commander Installer v1.9.3.8 Software ZIP 18.53 MB Jun 12, 2017
8T79S818I-08 IBIS Model Model - IBIS ZIP 188 KB Nov 23, 2014