The 8T33FS6221 is a bipolar monolithic differential clock fanout buffer. Designed for most demanding clock distribution systems, the 8T33FS6221 supports various applications that require the distribution of precisely aligned differential clock signals. Using SiGe technology and a fully differential architecture, the device offers very low skew outputs and superior digital signal characteristics. Target applications for this clock driver is high performance clock distribution in computing, networking and telecommunication systems.

The 8T33FS6221 is designed for low skew clock distribution systems and supports clock frequencies up to 2GHz. The device accepts two clock sources. The CLK0 input can be driven by PECL compatible signals, the CLK1 input accepts HSTL compatible signals. The selected input signal is distributed to 20 identical, differential PECL outputs. If VBB is connected to the nCLK0 or nCLK1 input and bypassed to GND by a 10nF capacitor, the 8T33FS6221 can be driven by single-ended PECL signals utilizing the VBB bias voltage output.

In order to meet the tight skew specification of the device, both outputs of a differential output pair should be terminated, even if only one output is used. In the case where not all ten outputs are used, the output pairs on the same package side as the parts being used on that side should be terminated.

The 8T33FS6221 can be operated from a single 3.3V or 2.5V supply.


  • 1:20 differential clock fanout buffer
  • 50ps typical device skew
  • SiGe technology
  • Maximum output frequency: 2GHz
  • PECL compatible differential clock outputs
  • PECL/ HSTL compatible differential clock inputs
  • Single 3.3V or 2.5V supply
  • Standard 52 lead LQFP package with exposed pad for enhanced thermal characteristics
  • Supports industrial temperature range
  • Lead-free Packaging

Product Options

Orderable Part ID Part Status Type Lead Count (#) Temp. Grade Pb (Lead) Free Carrier Type Buy Sample
Last Time Buy 52 I Yes Tray
Last Time Buy 52 I Yes Reel

Documentation & Downloads

Title Other Languages Type Format File Size Date
Datasheets & Errata
8T33FS6221 Datasheet Datasheet PDF 932 KB
PDN# : CQ-20-02 End of Life Process on Select Parts Product Discontinuation Notice PDF 720 KB
PCN# : A1601-02 Add UTAC China as Alternate Assembly Product Change Notice PDF 31 KB