SNLA475 October   2024 DS250DF410 , DS250DF810 , DS280BR810 , DS280BR820 , DS280DF810 , DS280MB810 , DS560MB410

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Codesign: 25GbE 4-Channel Retimer or Redriver with Crosspoint
    1. 2.1 DS250DF410 Retimer Overview
    2. 2.2 DS560MB410 Redriver Overview
    3. 2.3 Pin Comparison Table
    4. 2.4 Codesign Schematic Example
    5. 2.5 Notable Codesign Elements
      1. 2.5.1 Calibration Clock
      2. 2.5.2 SMBus Address
      3. 2.5.3 SMBus Controller Mode
      4. 2.5.4 SMBus Pull-Up Resistors
      5. 2.5.5 Interrupt Output
      6. 2.5.6 Mux Select Inputs
  6. 3Codesign: 25GbE 8-Channel Retimer or Redriver with Crosspoint
    1. 3.1 DS250DF810 and DS280DF810 Retimers Overview
    2. 3.2 DS280BR810, DS280BR820, and DS280MB810 Redrivers Overview
    3. 3.3 Pin Comparison Table
    4. 3.4 Codesign Schematic Example
    5. 3.5 Notable Codesign Elements
      1. 3.5.1 AC Coupling
      2. 3.5.2 Calibration Clock
      3. 3.5.3 SMBus Address
      4. 3.5.4 SMBus Controller Mode
      5. 3.5.5 SMBus Pull-Up Resistors
      6. 3.5.6 Interrupt Output
      7. 3.5.7 Mux Select Inputs
  7. 4Summary
  8. 5References

3.2 DS280BR810, DS280BR820, and DS280MB810 Redrivers Overview

The DS280BR810, DS280BR820, and DS280MB810 are 8 channel linear redriver devices supporting up to 28GBd NRZ. The key differentiation between DS280BR810 and DS280BR820 is that DS280BR810 has on-chip AC coupling for both RX and TX, while DS280BR820 has on-chip AC coupling for only RX. TI has observed better high speed performance with DS280BR820 over the DS280BR810, allowing for reach extension of over 17dB with DS280BR820 compared to over 15dB with DS280BR810. For new designs, TI recommends selecting DS280BR820 over DS280BR810. The DS280BR8x0 devices also have a limiting signal chain with fixed delay 3-tap TX FIR filter.

The DS280MB810 provides reach extension of over 17dB beyond normal ASIC to ASIC capability at 13.28GHz through the receiver CTLE. The differentiation between this device and DS280BR8x0 devices is that the device has a 2x2 cross point, but lacks the 3-tap TX FIR.

DS280BR810 Functional Block DiagramFigure 3-3 DS280BR810 Functional Block Diagram
DS280BR820 Functional Block DiagramFigure 3-4 DS280BR820 Functional Block Diagram
DS280MB810 Functional Block DiagramFigure 3-5 DS280MB810 Functional Block Diagram
DS280BR8x0 Pin ConfigurationFigure 3-6 DS280BR8x0 Pin Configuration
DS280MB810 Pin ConfigurationFigure 3-7 DS280MB810 Pin Configuration