Synchronous Ethernet Frequency Translator

The 840271I is a PLL-based Frequency Translator intended for use in telecommunication applications such as Synchronous Ethernet. The internal PLL translates Ethernet clock frequencies such as 125MHz (1Gb Ethernet), 156.25MHz (10GbE XAUI) and 161.1328MHz (10Gb Ethernet) to an output frequency of 25MHz. The PLL does not any require external components. The input frequency is selectable by a 2-pin interface. The 840271I is optimized for low cycle-to-cycle jitter on the 25MHz output signal. The input of the device accepts differential (LVPECL, LVDS, LVHSTL, SSTL, HCSL) or single-ended (LVCMOS) signals. The extended temperature range supports telecommunication and networking equipment requirements. The 840271I uses a small RoHS 6, 8-pin TSSOP package and is an effective solution for space-constrained applications.

Features

  • Clock frequency translator for Synchronous Ethernet applications
  • One single-ended output (LVCMOS or LVTTL levels), 16Ω output impedance
  • Differential input pair (CLK, nCLK) accepts LVPECL, LVDS, LVHSTL, SSTL, HCSL input levels
  • Supports input clock frequencies of: 125MHz, 156.25MHz or 161.1328MHz
  • Generates a 25MHz output clock signal
  • Internal resistor bias on nCLK pin allows the user to drive CLK input with external single-ended (LVCMOS/LVTTL) input levels
  • Internal PLL is optimized for low cycle-to-cycle jitter at the output
  • Full 3.3V or 2.5V supply voltage
  • -40°C to 85°C ambient operating temperature
  • Available in 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
840271BGILF Active PGG8 TSSOP 8 I Yes Tube Availability
840271BGILFT Active PGG8 TSSOP 8 I Yes Reel Availability

Technical Documentation

Title Other Languages Type Format File Size Date
Datasheets & Errata
840271i Final Data Sheet Datasheet PDF 713 KB Apr 6, 2014
Application Notes & White Papers
AN-828 Termination - LVPECL Application Note PDF 229 KB Jul 5, 2016
AN-835 Differential Input with VCMR being VIH Referenced Application Note PDF 77 KB May 10, 2014
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-836 Differential Input to Accept Single-ended Levels Application Note PDF 37 KB May 5, 2014
AN-834 Hot-Swap Recommendations Application Note PDF 67 KB May 5, 2014
AN-833 Differential Input Self Oscillation Prevention Application Note PDF 94 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# : A1511-01(R1) Add SPEL India as Alternate Assembly Location Product Change Notice PDF 596 KB Jan 27, 2016
PCN# : A1511-01 Add SPEL India as Alternate Assembly Location Product Change Notice PDF 544 KB Nov 12, 2015
PCN# : TB1303-02 Change of Tape & Reel Packing Method for Selective Products Product Change Notice PDF 361 KB Mar 23, 2013
Other
The IDT Consumer Products Advantage Overview PDF 4.01 MB Jun 30, 2017
The IDT Automotive Advantage Overview PDF 3.55 MB May 26, 2017
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 Products for Radio Applications 日本語 Product Brief PDF 2.34 MB Nov 29, 2016
IDT Clock Distribution Overview 日本語 Overview PDF 3.79 MB Apr 24, 2016

News & Additional Resources