FemtoClock® NG 12-Output Frequency Synthesizer

The 8T49N1012 has one fractional-feedback PLL that can be used for frequency synthesis. It is equipped with two integer and eight fractional output dividers, allowing the generation of up to ten different output frequencies, ranging from 8kHz to 1GHz. Eight of these frequencies are completely independent of each other and the inputs. Two more are related frequencies. The twelve outputs may select among LVPECL, LVDS, HSCL or LVCMOS output levels.

This functionality makes it ideal to be used in any frequency synthesis application, including 1G, 10G, 40G and 100G Synchronous Ethernet, OTN, and SONET/SDH, including ITU-T G.709 (2009) FEC rates. The device supports Output Enable inputs and Lock and LOS status outputs.


  • 0.3 ps RMS typical jitter (including spurs), 12 kHz to 20 MHz
  • Operating modes: locked to input signal and free-run
    • Digitally Controlled Oscillator (DCO) mode for software adjustment of operating frequency
  • Operates from a 10 MHz to 40 MHz fundamental-mode crystal
  • Accepts one LVPECL, LVDS, LVHSTL, HCSL, or LVCMOS input clock
    • Accepts frequencies ranging from 10 MHz up to 600 MHz
    • Clock input monitoring
  • Generates 12 LVPECL / LVDS / HCSL or 24 LVCMOS output clocks 
    • Output frequencies ranging from 8 kHz up to 1.0 GHz (diff)
    • Output frequencies ranging from 8 kHz up to 250 MHz (LVCMOS)
  • Two Output Enable control inputs
  • Lock and Loss-of-Signal status outputs
  • Programmable output de-skew adjustments in steps as small as 16 ps
  • Register programmable through I2C or via external I2C EEPROM
  • Bypass clock paths and reference Output for system tests
  • -40°C to +85°C ambient operating temperature
  • Packaged in 72-pin QFN, lead-free RoHS (6)
  • Supported by IDT Timing Commander Software

Product Options

Choose from the options below, or use the Custom Part Configuration Utility.
Orderable Part ID Part Status Pkg. Code Pkg. Type Lead Count (#) Temp. Grade Pb (Lead) Free Carrier Type Buy Sample
8T49N1012-998NLGI Active NLG72P2 VFQFPN 72 I Yes Tray Availability
8T49N1012-998NLGI8 Active NLG72P2 VFQFPN 72 I Yes Reel Availability

Technical Documentation

Title Other Languages Type Format File Size Date
Datasheets & Errata
8T49N1012 Datasheet Datasheet PDF 1.41 MB Jan 31, 2018
User Guides & Manuals
Timing Commander Installation Guide Guide PDF 497 KB Oct 6, 2013
Application Notes & White Papers
App Note 932 - Description for Startup and Calibration for UFT3G Family Application Note PDF 490 KB Aug 29, 2017
AN-949 UFT3G Register Write Sequences Application Note PDF 57 KB Oct 31, 2016
AN-828 Termination - LVPECL Application Note PDF 229 KB Jul 5, 2016
AN-831 The Crystal Load curve Application Note PDF 308 KB Sep 22, 2014
AN-860 8T49N28X Frequency Programming Guide Application Note PDF 214 KB Jun 4, 2014
AN-846 Termination - LVDS Application Note PDF 50 KB May 12, 2014
AN-845 Termination - LVCMOS Application Note PDF 62 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-803 Crystal Timing Budget and Accuracy for IDT Timing Clock Products Application Note PDF 44 KB May 7, 2014
AN-840 Jitter Specifications for Timing Signals Application Note PDF 349 KB May 7, 2014
AN-839 RMS Phase Jitter Application Note PDF 149 KB May 6, 2014
AN-838 Peak-to-Peak Jitter Calculations Application Note PDF 32 KB May 6, 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-832 Timing Budget and Accuracy Application Note PDF 48 KB May 5, 2014
AN-830 Quartz Crystal Drive Level Application Note PDF 59 KB May 4, 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-802 Crystal-Measuring Oscillator Negative Resistance Application Note PDF 52 KB Mar 11, 2014
AN-805 Recommended Ferrite Beads Application Note PDF 38 KB Jan 14, 2014
AN-801 Crystal-High Drive Level Application Note PDF 109 KB Jan 14, 2014
AN-806 Power Supply Noise Rejection Application Note PDF 353 KB Jan 14, 2014
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# : N1609-01 Minor Design Change on Select Devices Product Change Notice PDF 227 KB Oct 2, 2016
Timing Solutions Products Overview Overview PDF 964 KB Sep 19, 2018
Flexible Solutions for Fast Edge Rate and Low Phase Noise Requirements Overview PDF 154 KB Jul 1, 2016
8T49N1012 Schematic Schematic PDF 53 KB May 1, 2016
8T49N1012 FemtoClock NG 12-output Frequency Synthesizer Product Brief Product Brief PDF 631 KB May 1, 2016
IDT Clock Generation Overview 日本語 Overview PDF 1.83 MB Apr 28, 2016
IDT Clocks for Xilinx Ultrascale FPGAs Technical Brief PDF 256 KB Apr 25, 2016
IDT Clock Distribution Overview 日本語 Overview PDF 3.79 MB Apr 24, 2016
IDT Clocks for Altera's Stratix V and Arria V/X FPGAs Technical Brief PDF 238 KB Feb 7, 2016
IDT Clocks for SMPTE and Xilinx® 7 Series FPGAs Technical Brief PDF 566 KB Oct 19, 2015
IDT Jitter Attenuator Product Overview 简体中文 Overview PDF 1.95 MB Oct 22, 2014

Software & Tools

Title Other Languages Type Format File Size Date
Timing Commander Installer v1.11.0.15609 Software ZIP 18.58 MB Sep 17, 2018
8T49N1012 Timing Commander Personality File v0.11 Software TCP 3.13 MB Jul 14, 2016
8T49N1012 IBIS Model Model - IBIS ZIP 390 KB May 1, 2016

Evaluation Boards

Part Number Title Sort ascending
EVK-8T49N1012 Evaluation Kit for 8T49N1012