The 281 field programmable spread spectrum clock synthesizer generates up to three high-quality, high-frequency clock outputs including multiple reference clocks from a low-frequency crystal input. It is designed to replace crystals, crystal oscillators and stand alone spread spectrum devices in most electronic systems. Using IDT's VersaClockTM software to configure PLLs and outputs, the 281 contains a One-Time Programmable (OTP) ROM for field programmability. Programming features include input/output frequencies, spread spectrum amount and eight selectable configuration registers. Using Phase-Locked Loop (PLL) techniques, the device runs from a standard fundamental mode, inexpensive crystal, or clock. It can replace multiple crystals and oscillators, saving board space and cost. The 281 is also available in factory programmed custom versions for high-volume applications.

Features

  • Packaged as 16-pin TSSOP – Pb-free, RoHS compliant
  • Eight addressable registers
  • Replaces multiple crystals and oscillators
  • Output frequencies up to 200 MHz at 3.3 V
  • Configurable Spread Spectrum Modulation
  • Input crystal frequency of 5 to 27 MHz
  • Input clock frequency of 3 to 166 MHz
  • Up to three reference outputs
  • Operating voltages of 3.3 V
  • VDDO output control from 1.8 V to 3.3 V
  • Controllable output drive levels
  • Advanced, low-power CMOS process

Product Options

Orderable Part ID Part Status Pkg. Type Lead Count (#) Temp. Grade Pb (Lead) Free Carrier Type Package Buy Sample
281PGILF Obsolete TSSOP 16 I Yes Tube Package Info
Availability
281PGILFT Obsolete TSSOP 16 I Yes Reel Package Info
Availability
281PGLF Obsolete TSSOP 16 C Yes Tube Package Info
Availability
281PGLFT Obsolete TSSOP 16 C Yes Reel Package Info
Availability

Documentation & Downloads

Title Other Languages Type Format File Size Date
Datasheets & Errata
281 Datasheet Datasheet PDF 275 KB
User Guides & Manuals
VersaClock II User Guide Manual Manual - User Reference PDF 612 KB
Application Notes & White Papers
AN-828 Termination - LVPECL Application Note PDF 322 KB
AN-831 The Crystal Load curve Application Note PDF 395 KB
AN-845 Termination - LVCMOS Application Note PDF 146 KB
AN-844 Termination - AC Coupling Clock Receivers Application Note PDF 170 KB
AN-842 Thermal Considerations in Package Design and Selection Application Note PDF 495 KB
AN-803 Crystal Timing Budget and Accuracy for IDT Timing Clock Products Application Note PDF 128 KB
AN-840 Jitter Specifications for Timing Signals Application Note PDF 442 KB
AN-838 Peak-to-Peak Jitter Calculations Application Note PDF 115 KB
AN-839 RMS Phase Jitter Application Note PDF 233 KB
AN-832 Timing Budget and Accuracy Application Note PDF 131 KB
AN-834 Hot-Swap Recommendations Application Note PDF 153 KB
AN-837 Overdriving the Crystal Interface Application Note PDF 133 KB
AN-836 Differential Input to Accept Single-ended Levels Application Note PDF 120 KB
AN-835 Differential Input with VCMR being VIH Referenced Application Note PDF 160 KB
AN-830 Quartz Crystal Drive Level Application Note PDF 143 KB
AN-827 Application Relevance of Clock Jitter Application Note PDF 1.15 MB
AN-815 Understanding Jitter Units Application Note PDF 565 KB
AN-802 Crystal-Measuring Oscillator Negative Resistance Application Note PDF 136 KB
AN-801 Crystal-High Drive Level Application Note PDF 202 KB
AN-806 Power Supply Noise Rejection Application Note PDF 438 KB
AN-805 Recommended Ferrite Beads Application Note PDF 121 KB
PCNs & PDNs
PCN# : TB1403-01 Changed in Carrier Tape, Plastic Reel and Quantity per Reel on TSSOP-14, TSSOP-16 Product Change Notice PDF 663 KB
PCN# : A1309-01 Changed of Traceability Mark Format Product Change Notice PDF 439 KB
Downloads
VersaClock II Desktop Software Setup Software ZIP 6.24 MB