NOTICE - The following device(s) are recommended alternatives:

The 841S104I-02 is a PLL-based clock synthesizer specifically designed for Ethernet and SONET™ Clock applications. This device generates either a 156.25MHz or 155.52MHz differential HCSL clock from an input reference of either 25MHz or 19.44MHz. The input reference may be derived from an external source or by the addition of a 25MHz or a 19.44MHz crystal to the on-chip crystal oscillator. An external reference may be applied to the XTAL_IN pin with the XTAL_OUT pin left floating. An I2C bus interface is used to enable or disable each individual clock output. The 841S104I-02 is available in a lead-free 24-Lead package.


  • Four 0.7V current mode differential HCSL output pairs
  • Crystal oscillator interface: 25MHz or 19.44MHz
  • Output frequency: 156.25MHz or 155.52MHz
  • RMS phase jitter @ 156.25MHz (12kHz – 20MHz): 0.691ps (typical)
  • Cycle-to-cycle jitter: 25ps (maximum)
  • I2C support with readback capabilities up to 400kHz
  • 3.3V operating supply mode
  • -40°C to 85°C ambient operating temperature
  • Available lead-free (RoHS 6) package

Product Options

Orderable Part ID Part Status Pkg. Code Pkg. Type Lead Count (#) Temp. Grade Pb (Lead) Free Carrier Type Buy Sample
841S104BGI-02LF Obsolete PGG24 TSSOP 24 I Yes Tube
841S104BGI-02LFT Obsolete PGG24 TSSOP 24 I Yes Reel

Technical Documentation

Title Other Languages Type Format File Size Date
Datasheets & Errata
ICS841S104I-02 Datasheet Datasheet PDF 312 KB
Application Notes & White Papers
AN-828 Termination - LVPECL Application Note PDF 229 KB
AN-831 The Crystal Load curve Application Note PDF 308 KB
AN-842 Thermal Considerations in Package Design and Selection Application Note PDF 403 KB
AN-803 Crystal Timing Budget and Accuracy for IDT Timing Clock Products Application Note PDF 44 KB
AN-840 Jitter Specifications for Timing Signals Application Note PDF 349 KB
AN-839 RMS Phase Jitter Application Note PDF 149 KB
AN-838 Peak-to-Peak Jitter Calculations Application Note PDF 32 KB
AN-834 Hot-Swap Recommendations Application Note PDF 67 KB
AN-837 Overdriving the Crystal Interface Application Note PDF 50 KB
AN-832 Timing Budget and Accuracy Application Note PDF 48 KB
AN-830 Quartz Crystal Drive Level Application Note PDF 59 KB
AN-827 Application Relevance of Clock Jitter Application Note PDF 1.06 MB
AN-815 Understanding Jitter Units Application Note PDF 476 KB
AN-802 Crystal-Measuring Oscillator Negative Resistance Application Note PDF 52 KB
AN-805 Recommended Ferrite Beads Application Note PDF 38 KB
AN-801 Crystal-High Drive Level Application Note PDF 109 KB
AN-806 Power Supply Noise Rejection Application Note PDF 353 KB
PCN# : TB1503-01R1 Carrier Tape Standardization for Selective Packages Product Change Notice PDF 333 KB
PCN# : TB1504-01R1 Qty per Reel Standardization for Selective Packages Product Change Notice PDF 95 KB
PDN# : CQ-15-04 Quarterly Market Declined PDN Product Discontinuation Notice PDF 545 KB
PCN# : TB1503-01 Carrier Tape Standardization for Selective Packages Product Change Notice PDF 291 KB
PCN# : TB1504-01 Qty per Reel Standardization for Selective Packages Product Change Notice PDF 50 KB
PCN# : TB1303-02 Change of Tape & Reel Packing Method for Selective Products Product Change Notice PDF 361 KB
Timing Solutions Products Overview Overview PDF 4.11 MB
IDT Products for Radio Applications 日本語 Product Brief PDF 2.34 MB
IDT Clock Generation Overview 日本語 Overview PDF 1.83 MB
IDT Clock Distribution Overview 日本語 Overview PDF 3.79 MB

Software & Tools

Title Other Languages Type Format File Size Date
ICS841S104I-02 IBIS Model Model - IBIS ZIP 75 KB