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813N252DI-02 - Block Diagram
813N252DI-02 - Pin Assignment


Jitter Attenuator & Femtoclock NG® Multiplier

The 813N252I-02 device uses IDT's fourth generation FemtoClock® NG technology for optimal high clock frequency and low phase noise performance, combined with a low power consumption and high power supply noise rejection. The 813N252DI-02 is a PLL based synchronous multiplier that is optimized for PDH or SONET to Ethernet clock jitter attenuation and frequency translation.

The 813N252DI-02 is a fully integrated Phase Locked loop utilizing a FemtoClock NG Digital VCXO that provides the low jitter, high frequency SONET/PDH output clock that easily meets OC-48 jitter requirements. This VCXO technology simplifies PLL design by replacing the pullable crystal requirement of analog VCXOs with a fixed 27MHz generator crystal. Jitter attenuation down to 10Hz is provided by an external loop filter. Pre-divider and output divider multiplication ratios are selected using device selection control pins. The multiplication ratios are optimized to support most common clock rates used in PDH, SONET and Ethernet applications. The device requires the use of an external, inexpensive fundamental mode 27MHz crystal. The device is packaged in a space-saving 32-VFQFN package and supports industrial temperature range.


  • Fourth generation FemtoClock® NG technology
  • Two LVPECL output pairs
  • Each output supports independent frequency selection at 25MHz, 125MHz, 156.25MHz and 312.5MHz
  • Two differential inputs support the following input types: LVPECL, LVDS, LVHSTL, SSTLHCSL
  • Accepts input frequencies from 8kHz to 155.52MHz including 8kHz, 1.544MHz, 2.048MHz, 19.44MHz, 25MHz, 77.76MHz, 125MHz and 155.52MHz
  • Crystal interface optimized for a 27MHz, 10pF parallel resonant crystal
  • Attenuates the phase jitter of the input clock by using a low-cost fundamental mode crystal
  • Customized settings for jitter attenuation and reference tracking using an external loop filter connection
  • FemtoClock NG frequency multiplier provides low jitter, high frequency output
  • Absolute pull range: ±100ppm
  • Power supply noise rejection (PSNR): -95dB (typical)
  • FemtoClock NG VCXO frequency: 2500MHz
  • RMS phase jitter @ 156.25MHz, using a 27MHz crystal (12kHz ‘- 20MHz): 0.6ps (typical)
  • RMS phase jitter @ 125MHz, using a 27MHz crystal (12kHz ‘- 20MHz): 0.63ps (typical)
  • 3.3V supply voltage
  • -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 Voltage (V)Output Skew (ps)Phase Jitter Typ RMS (ps)Phase Jitter Max RMS (ps)
2LVPECL25.000000 - 312.5000000.008000 - 155.5200002LVPECL, LVHSTL, SSTL, HCSL, LVDS23.33.3800.600

Product Options

Orderable Part IDPart StatusPkg. CodePkg. TypeLead Count (#)Temp. GradePb (Lead) FreeCarrier TypeSample & Buy
813N252DKI-02LFActiveNLG32P3VFQFPN32IYesTrayCheck Availability
813N252DKI-02LFTActiveNLG32P3VFQFPN32IYesReelCheck Availability


Technical Documentation

Title Other Languages Type Format File Size Datesort icon
Datasheets & Errata
813N252DI-02 Data Sheet Datasheet PDF 482 KB Sep 4, 2015
Apps Notes & White Papers
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-842 Thermal Considerations in Package Design and Selection Application Note PDF 403 KB May 12, 2014
show all (15)
AN-840 Jitter Specifications for Timing Signals Application Note PDF 349 KB May 8, 2014
AN-839 RMS Phase Jitter Application Note PDF 149 KB May 7, 2014
AN-838 Peak-to-Peak Jitter Calculations Application Note PDF 32 KB May 7, 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-830 Quartz Crystal Drive Level Application Note PDF 59 KB May 5, 2014
AN-815 Understanding Jitter Units Application Note PDF 476 KB Apr 24, 2014
AN-827 Application Relevance of Clock Jitter Application Note PDF 1.06 MB Apr 24, 2014
AN-802 Crystal-Measuring Oscillator Negative Resistance Application Note PDF 52 KB Mar 12, 2014
AN-806 Power Supply Noise Rejection Application Note PDF 353 KB Jan 15, 2014
AN-801 Crystal-High Drive Level Application Note PDF 109 KB Jan 15, 2014
AN-805 Recommended Ferrite Beads Application Note PDF 38 KB Jan 15, 2014
PCN# : A1511-01(R1) Add SPEL India as Alternate Assembly Location Product Change Notice PDF 596 KB Jan 28, 2016
PCN# : A1511-01 Add SPEL India as Alternate Assembly Location Product Change Notice PDF 544 KB Nov 13, 2015
PCN# : W1308-01 Change of Passivation Thickness Product Change Notice PDF 941 KB Sep 11, 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