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557-03 - Block Diagram


2 Output PCI-Express GEN1 Clock Source

The 557-03 is a spread spectrum clock generator that supports PCI-Express Gen 1 and Ethernet requirements. The device is used for PC or embedded systems to substantially reduce electromagnetic interference (EMI). The device provides two differential (HCSL) spread spectrum outputs. The spread type and amount are configured via select pin. Using IDT's patented Phase-Locked Loop (PLL) techniques, the device takes a 25 MHz crystal input and produces two pairs of differential outputs at 25 MHz, 100 MHz, 125 MHz or 200 MHz clock frequencies for HCSL, and 25 MHz or 100 MHz for LVDS.


  • Packaged in 16-pin TSSOP
  • RoHS 5 (green) or RoHS 6 (green and lead free) compliant packaging
  • Supports HCSL or LVDS output levels
  • Operating voltage of 3.3 V
  • Input frequency of 25 MHz
  • Jitter 60 ps (cycle-to-cycle)
  • Spread Spectrum capability
  • Industrial and commercial temperature ranges
  • For PCIe Gen2 applications, see the 5V41065
  • For PCIe Gen3 applications, see the 5V41235

Product Specification

Output TypeOutput Freq Range (MHz)Input Freq (MHz)Inputs (#)Input TypeOutput Banks (#)Core Voltage (V)Output Voltage (V)
HCSL25.000000, 100.000000, 125.000000, 200.00000025.0000001LVCMOS, Crystal13.33.3

Product Options

Orderable Part IDPart StatusPkg. CodePkg. TypeLead Count (#)Temp. GradePb (Lead) FreeCarrier TypeSample & Buy
557G-03LFActivePGG16TSSOP16CYesTubeCheck Availability
557G-03LFTActivePGG16TSSOP16CYesReelCheck Availability
557GI-03LFActivePGG16TSSOP16IYesTubeCheck Availability
557GI-03LFTActivePGG16TSSOP16IYesReelCheck Availability


Technical Documentation

Title Other Languages Type Format File Size Datesort icon
Datasheets & Errata
557-03 Datasheet Datasheet PDF 160 KB Dec 6, 2011
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-843 PCI Express Reference Clock Requirements Application Note PDF 1.81 MB May 13, 2014
show all (14)
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-838 Peak-to-Peak Jitter Calculations Application Note PDF 32 KB May 7, 2014
AN-839 RMS Phase Jitter Application Note PDF 149 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-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-808 PCI Express/HCSL Termination Application Note PDF 54 KB Jan 15, 2014
AN-805 Recommended Ferrite Beads Application Note PDF 38 KB Jan 15, 2014
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
PCN# : A1511-01(R1) Add SPEL India as Alternate Assembly Location Product Change Notice PDF 596 KB Jan 28, 2016
show all (8)
PCN# : A1511-01 Add SPEL India as Alternate Assembly Location Product Change Notice PDF 544 KB Nov 13, 2015
PCN# : TB1403-01 Changed in Carrier Tape, Plastic Reel and Quantity per Reel on TSSOP-14, TSSOP-16 Product Change Notice PDF 663 KB Apr 8, 2014
PCN# : A1309-01 Changed of Traceability Mark Format Product Change Notice PDF 439 KB Oct 11, 2013
PCN# : TB1303-02 Change of Tape & Reel Packing Method for Selective Products Product Change Notice PDF 361 KB Mar 24, 2013
PCN# : A1111-01 ADD ALTERNATE ASSEMBLY SITES Product Change Notice PDF 114 KB Dec 14, 2011
IDT PCI Express Solutions Overview 简体中文, 日本語 Overview PDF 945 KB Aug 4, 2016
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

Software & Tools

Title Type Format File Size Datesort icon
557-03 IBIS Model Model - IBIS ZIP 4 KB Mar 6, 2007

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