Field Programmable SS Clock Synthesizer

The IDT251 is a low cost, single-output, field programmable clock synthesizer. The IDT251 can generate an output frequency from 314 kHz to 200 MHz and may employ Spread Spectrum techniques to reduce system electro-magnetic interference (EMI). Using IDT's VersaClock™ software to configure the PLL and output, the IDT251 contains a One-Time Programmable (OTP) ROM to allow field programmability. Programming features include 4 selectable configuration registers. The device employs Phase-Locked Loop (PLL) techniques to run from a standard fundamental mode, inexpensive crystal, or clock. It can replace multiple crystals and oscillators, saving board space and cost. The device also has a power-down feature that tri-states the clock outputs and turns off the PLLs when the PDTS pin is taken low. The IDT251 is also available in factory programmed custom versions for high-volume applications.

Features

  • 8-pin SOIC package
  • Four addressable registers
  • Input crystal frequency of 5 to 27 MHz
  • Clock input frequency of 3 to 150 MHz
  • Output clock frequencies up to 200 MHz
  • Configurable Spread Spectrum Modulation
  • Operating voltage of 3.3 V
  • Replaces multiple crystals and oscillators
  • Controllable output drive levels
  • Advanced, low-power CMOS process
  • Available in RoHS compliant packaging
  • click here for VersaClock Software page

Product Options

Orderable Part ID Part Status Pkg. Code Pkg. Type Lead Count (#) Temp. Grade Pb (Lead) Free Carrier Type Buy Sample
251PMILF Active DCG8 SOIC 8 I Yes Tube Availability
251PMILFT Active DCG8 SOIC 8 I Yes Reel Availability

Technical Documentation

Title Other Languages Type Format File Size Date
Datasheets & Errata
251 Datasheet Datasheet PDF 131 KB Oct 11, 2017
Application Notes & White Papers
AN-828 Termination - LVPECL Application Note PDF 229 KB Jul 5, 2016
AN-815 Understanding Jitter Units Application Note PDF 476 KB Apr 23, 2014
AN-831 The Crystal Load curve Application Note PDF 308 KB Sep 22, 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-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-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-802 Crystal-Measuring Oscillator Negative Resistance Application Note PDF 52 KB Mar 11, 2014
AN-827 Application Relevance of Clock Jitter Application Note PDF 1.06 MB Apr 23, 2014
AN-806 Power Supply Noise Rejection Application Note PDF 353 KB Jan 14, 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
PCNs & PDNs
PCN# : A1602-01(R1) Add Greatek Taiwan as Alternate Assembly Product Change Notice PDF 611 KB Apr 13, 2016
PCN# : A1602-01 Add Greatek Taiwan as Alternate Assembly Product Change Notice PDF 611 KB Feb 14, 2016
PCN# : TB1504-01R1 Qty per Reel Standardization for Selective Packages Product Change Notice PDF 95 KB Oct 21, 2015
PCN# : TB1504-01 Qty per Reel Standardization for Selective Packages Product Change Notice PDF 50 KB Jul 20, 2015
PCN# : TB1303-02 Change of Tape & Reel Packing Method for Selective Products Product Change Notice PDF 361 KB Mar 23, 2013
PCN# A-0607-06 MMT Thailand as Alternate Assembly Facility for PLCC, SOIC 150mil/300mil Product Change Notice PDF 223 KB Oct 5, 2006
Other
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

News & Additional Resources