The QLx4300-S45 is a settable quad receive-side equalizer with extended functionality for advanced protocols operating with line rates up to 3. 125Gb/s such as InfiniBand (SDR) and 10GBase-CX4. The QLx4300-S45 compensates for the frequency dependent attenuation of copper twin-axial cables, extending the signal reach up to 40m on 24AWG cable. The small form factor, highly-integrated quad design is ideal for high-density data transmission applications including active copper cable assemblies. The four equalizing filters within the QLx4300-S45 can each be set to one of 32 compensation levels, providing optimal signal fidelity for a given media and length. The compensation level for each filter can be set by either (a) three external control pins or (b) a serial bus interface. When the external control pins are used, 18 of the 32 boost levels are available for each channel. If the serial bus is used, all 32 compensation levels are available. Operating on a single 1. 2V power supply, the QLx4300-S45 enables per channel throughputs of up to 3. 125Gb/s while supporting the lower data rates of 2. 5Gb/s and 1. 5Gb/s. The QLx4300-S45 uses current mode logic (CML) inputs/outputs and is packaged in a 4mmx7mm 46 lead QFN. Individual lane impedance select support is included for module applications.


  • Supports data rates up to 3.125Gb/s
  • Low power (78mW per channel)
  • Low latency (<500ps)
  • Four equalizers in a 4mmx7mm QFN package for straight route-through architecture and simplified routing
  • Each equalizer boost is independently pin selectable and programmable
  • Beacon signal support and line silence preservation
  • 1.2V supply voltage
  • Individual channel power-down (impedance select) Benefits
  • Thinner gauge cable
  • Extends cable reach greater than 3x
  • Improved BER


  • InfiniBand (SDR)
  • 10GBase-CX4
  • PCI Express (Gen 1)
  • DisplayPort
  • XAUI
  • SAS (10)
  • High-speed active cable assemblies
  • High-speed printed circuit board (PCB) traces

Product Options

Orderable Part ID Part Status Pkg. Type Carrier Type Buy Sample
Active QFN Reel
Active QFN Reel

Documentation & Downloads

Title Other Languages Type Format File Size Date
Datasheets & Errata
QLx4300-S45 Datasheet Datasheet PDF 2.58 MB
User Guides & Manuals
EBL4300CI-EVALZ User Guide Manual PDF 691 KB
IDT Products for Radio Applications 日本語 Product Brief PDF 2.34 MB