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83948I - Block Diagram
83948I - Pinout


Low Skew,1-to-12 Differential-to-LVCMOS/LVTTL Fanout Buffer

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

The 83948I is a low skew, 1-to-12 Differential-to-LVCMOS/LVTTL Fanout Buffer and a member of the family of High Performance Clock Solutions from IDT. The 83948I has two selectable clock inputs. The CLK, nCLK pair can accept most standard differential input levels. The LVCMOS_CLK can accept LVCMOS or LVTTL input levels. The low impedance LVCMOS/LVTTL outputs are designed to drive 50Ω series or parallel terminated transmission lines. The effective fanout can be increased from 12 to 24 by utilizing the ability of the outputs to drive two series terminated lines. The 83948I is characterized at full 3.3V core/3.3V output. Guaranteed output and part-to-part skew characteristics make the 83948I ideal for those clock distribution applications demanding well defined performance and repeatability.


  • Twelve LVCMOS/LVTTL outputs
  • Selectable differential CLK/nCLK or LVCMOS/LVTTL clock input
  • CLK/nCLK pair can accept the following differential input levels: LVPECL, LVDS, LVHSTL, SSTLHCSL
  • LVCMOS_CLK supports the following input types: LVCMOSLVTTL
  • Maximum output frequency: 250MHz
  • Output skew: 350ps (maximum)
  • Part-to-part skew: 1.5ns (maximum)
  • 3.3V core, 3.3V output
  • -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 Skew (ps)Additive Phase Jitter Typ RMS (ps)
12LVCMOS0.000000 - 250.0000000.000000 - 250.0000002LVCMOS, HSTL, LVDS, LVPECL, SSTL, HCSL13.3350

Product Options

Orderable Part IDPart StatusPkg. CodePkg. TypeLead Count (#)Temp. GradePb (Lead) FreeCarrier TypeSample & Buy
83948AYILFLast Time BuyPRG32TQFP32IYesTrayCheck Availability
83948AYILFTLast Time BuyPRG32TQFP32IYesReelCheck Availability


Technical Documentation

Title Other Languages Type Format File Size Datesort icon
Datasheets & Errata
83948I Datasheet Datasheet PDF 285 KB May 19, 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-845 Termination - LVCMOS Application Note PDF 62 KB May 13, 2014
show all (12)
AN-842 Thermal Considerations in Package Design and Selection Application Note PDF 403 KB May 12, 2014
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-834 Hot-Swap Recommendations Application Note PDF 67 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-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
PDN# : CQ-16-01 PRODUCT DISCONTINUANCE NOTICE Product Discontinuation Notice PDF 552 KB May 4, 2016
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
show all (10)
PCN# : TB1504-01R1 Qty per Reel Standardization for Selective Packages Product Change Notice PDF 95 KB Oct 22, 2015
PCN# : TB1504-01 Qty per Reel Standardization for Selective Packages Product Change Notice PDF 50 KB Jul 21, 2015
PCN# : A1401-02 Alternate Copper Wire Assembly Site Product Change Notice PDF 36 KB Feb 16, 2014
PCN# : A1309-01 Changed of Traceability Mark Format Product Change Notice PDF 439 KB Oct 11, 2013
PDN# : N-12-22R2 PRODUCT DISCONTINUANCE NOTICE Product Discontinuation Notice PDF 363 KB Jun 14, 2013
PCN# : TB1303-01 Change of Carrier Tape for TQFP-32, TQFP-48 Product Change Notice PDF 472 KB Mar 31, 2013
PDN# : N-12-22R1 PRODUCT DISCONTINUANCE NOTICE Product Discontinuation Notice PDF 209 KB Feb 28, 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