The 8T79S308 is a fully integrated signal fanout buffer for high-performance, low additive phase noise applications. The main function of the device is the distribution and fanout of high-frequency clocks or low-frequency synchronization signals. The 8T79S308 is optimized to deliver very low phase noise clocks and precise, low-skew outputs, low device-to-device skew characteristics and fast output rise/fall times help the system design to achieve deterministic clock phase relationship across devices.

The device distributes the input signals (IN_0, IN_1) to two fanout banks. A input select logic allows the device to operate as 1:8 buffer, dual 1:4 buffers, and to cross the input signals. The propagation delay in both outputs banks is designed for equal delay to support fixed phase relationships between both banks. All outputs are very flexible in LVPECL/LVDS output style configuration, output signal termination, and allow both DC and AC coupling. Outputs can be individually disabled through a serial interface.

The device is packaged in a lead-free (RoHS 6) 40-VFQFPN package. The extended temperature range supports wireless infrastructure, telecommunication, and networking end equipment requirements. The 8T79S308 is a member of the high-performance clock family from IDT.

Features

  • High-performance, flexible clock/data/1PPS fanout buffer
  • Low phase noise floor: -160dBc/Hz (156.56MHz clock)
  • Integrated phase noise of 50fs RMS typical (12kHz–20MHz)
  • Flexible input selection (single fanout, dual buffer, switch)
  • Eight differential outputs, organized in two banks of four outputs
  • Low-power LVPECL/LVDS outputs
  • Individually configured outputs through an I2C interface (style, amplitude, enable)
  • Supported clock frequency range: 0 to 3GHz
  • 3.3V/2.5V core and 3.3V/2.5V/1.8V output supply voltage
  • Selectable I2C I/O interface voltage: 1.8V and VDD
  • Integrated low dropout regulators (LDOs) for excellent power supply noise rejection
  • Package: 6 × 6 mm 40-VFQFPN
  • Temperature range: -40°C to +105°C

Product Options

Orderable Part ID Part Status Pkg. Code Pkg. Type Lead Count (#) Temp. Grade Pb (Lead) Free Carrier Type Buy Sample
8T79S308NLGI Active NLG40P2 VFQFPN 40 I Yes Tray
Availability
8T79S308NLGI8 Active NLG40P2 VFQFPN 40 I Yes Reel
Availability
8T79S308NLGI/W Active NLG40P2 VFQFPN 40 I Yes Reel
Availability

Documentation & Downloads

Title Other Languages Type Format File Size Date
Datasheets & Errata
8T79S308 Datasheet Datasheet PDF 669 KB
Application Notes & White Papers
AN-828 Termination - LVPECL Application Note PDF 322 KB
AN-846 Termination - LVDS Application Note PDF 133 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-840 Jitter Specifications for Timing Signals Application Note PDF 442 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-834 Hot-Swap Recommendations Application Note PDF 153 KB
AN-833 Differential Input Self Oscillation Prevention Application Note PDF 180 KB
AN-815 Understanding Jitter Units Application Note PDF 565 KB
AN-827 Application Relevance of Clock Jitter Application Note PDF 1.15 MB
AN-805 Recommended Ferrite Beads Application Note PDF 121 KB
PCNs & PDNs
PCN# : A1904-01 Add Greatek, Taiwan as an Alternate Assembly Facility Product Change Notice PDF 983 KB
Downloads
8T79S308 IBIS Model Model - IBIS ZIP 124 KB
Other
Timing Solutions Products Overview Overview PDF 4.11 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
IDT Fanout Buffers Product Overview Product Brief PDF 739 KB
High-Performance, Low-Phase Noise Clocks Buffers product brief Product Brief PDF 378 KB

Boards & Kits