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

This device is factory-configurable. Try the Custom Part Configuration Utility.
Part Number Part Status Pkg. Type Lead Count (#) Temp. Grade Pb (Lead) Free Carrier Type Buy Sample
Active VFQFPN 72 I Yes Tray
Active VFQFPN 72 I Yes Reel

Documentation & Downloads

Title language Type Format File Size Date
Datasheets & Errata
8T49N1012 Datasheet Datasheet PDF 1.43 MB
User Guides & Manuals
Timing Commander Installation Guide Guide PDF 497 KB
Application Notes & White Papers
App Note 932 - Description for Startup and Calibration for UFT3G Family Application Note PDF 604 KB
AN-828 Termination - LVPECL Application Note PDF 322 KB
AN-831 The Crystal Load curve Application Note PDF 395 KB
AN-860 8T49N28X Frequency Programming Guide Application Note PDF 301 KB
AN-846 Termination - LVDS Application Note PDF 133 KB
AN-845 Termination - LVCMOS Application Note PDF 146 KB
AN-844 Termination - AC Coupling Clock Receivers Application Note PDF 170 KB
AN-842 Thermal Considerations in Package Design and Selection Application Note PDF 495 KB
AN-840 Jitter Specifications for Timing Signals Application Note PDF 442 KB
AN-838 Peak-to-Peak Jitter Calculations Application Note PDF 115 KB
AN-839 RMS Phase Jitter Application Note PDF 233 KB
AN-832 Timing Budget and Accuracy Application Note PDF 131 KB
AN-833 Differential Input Self Oscillation Prevention Application Note PDF 180 KB
AN-834 Hot-Swap Recommendations Application Note PDF 153 KB
AN-836 Differential Input to Accept Single-ended Levels Application Note PDF 120 KB
AN-835 Differential Input with VCMR being VIH Referenced Application Note PDF 160 KB
AN-830 Quartz Crystal Drive Level Application Note PDF 143 KB
AN-827 Application Relevance of Clock Jitter Application Note PDF 1.15 MB
AN-815 Understanding Jitter Units Application Note PDF 565 KB
AN-802 Crystal-Measuring Oscillator Negative Resistance Application Note PDF 136 KB
AN-801 Crystal-High Drive Level Application Note PDF 202 KB
AN-806 Power Supply Noise Rejection Application Note PDF 438 KB
AN-805 Recommended Ferrite Beads Application Note PDF 121 KB
AN-803 Crystal Timing Budget and Accuracy for Renesas Timing Clock Products Application Note PDF 108 KB
PCN# : TP1912-01 Resolved Timing Marginality within the Feedback Divider Circuity Product Change Notice PDF 163 KB
PCN# : A1904-01 Add Greatek, Taiwan as an Alternate Assembly Facility Product Change Notice PDF 983 KB
PCN#: TP1901-01 Datasheet Correction for I2C Read Sequence Diagrams for the UFT Product Family Product Change Notice PDF 454 KB
PCN# : A1611-02 Add JCET China as Alternate Assembly and Change of Material Set at Alternate Assembly Location Product Change Notice PDF 583 KB
PCN# : N1609-01 Minor Design Change on Select Devices Product Change Notice PDF 227 KB
Timing Commander Installer (v1.16.4) Software ZIP 19.79 MB
8T49N1012 Timing Commander Personality File v0.11 Software TCP 3.13 MB
8T49N1012 IBIS Model Model - IBIS ZIP 390 KB
8T49N1012 FemtoClock NG 12-output Frequency Synthesizer Product Brief Product Brief PDF 631 KB
8T49N1012 Schematic Schematic PDF 53 KB
IDT Clock Generation Overview 日本語 Overview PDF 1.83 MB
IDT Clocks for Xilinx Ultrascale FPGAs Technical Brief PDF 256 KB
IDT Clocks for Altera's Stratix V and Arria V/X FPGAs Technical Brief PDF 238 KB
IDT Clocks for SMPTE and Xilinx® 7 Series FPGAs Technical Brief PDF 566 KB
IDT Jitter Attenuator Product Overview 简体中文 Overview PDF 1.95 MB

Boards & Kits

Part Number Title Type Company
EVK-8T49N1012 Evaluation Kit for 8T49N1012 Evaluation Renesas