SNLS647G december   2019  – july 2023 DP83826E , DP83826I

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Mode Comparison Tables
  7. 6 Pin Configuration and Functions (ENHANCED Mode)
  8. 7 Pin Configuration and Functions (BASIC Mode)
  9. 8 Specifications
    1. 8.1 Absolute Maximum Ratings
    2. 8.2 ESD Ratings
    3. 8.3 Recommended Operating Conditions
    4. 8.4 Thermal Information
    5. 8.5 Electrical Characteristics
    6. 8.6 Timing Requirements
    7. 8.7 Timing Diagrams
    8. 8.8 Typical Characteristics
  10. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1  Auto-Negotiation (Speed/Duplex Selection)
      2. 9.3.2  Auto-MDIX Resolution
      3. 9.3.3  Energy Efficient Ethernet
        1. 9.3.3.1 EEE Overview
        2. 9.3.3.2 EEE Negotiation
      4. 9.3.4  EEE for Legacy MACs Not Supporting 802.3az
      5. 9.3.5  Wake-on-LAN Packet Detection
        1. 9.3.5.1 Magic Packet Structure
        2. 9.3.5.2 Magic Packet Example
        3. 9.3.5.3 Wake-on-LAN Configuration and Status
      6. 9.3.6  Low Power Modes
        1. 9.3.6.1 Active Sleep
        2. 9.3.6.2 IEEE Power-Down
        3. 9.3.6.3 Deep Power Down State
      7. 9.3.7  RMII Repeater Mode
      8. 9.3.8  Clock Output
      9. 9.3.9  Media Independent Interface (MII)
      10. 9.3.10 Reduced Media Independent Interface (RMII)
      11. 9.3.11 Serial Management Interface
        1. 9.3.11.1 Extended Register Space Access
        2. 9.3.11.2 Write Address Operation
        3. 9.3.11.3 Read Address Operation
        4. 9.3.11.4 Write (No Post Increment) Operation
        5. 9.3.11.5 Read (No Post Increment) Operation
        6. 9.3.11.6 Example Write Operation (No Post Increment)
      12. 9.3.12 100BASE-TX
        1. 9.3.12.1 100BASE-TX Transmitter
          1. 9.3.12.1.1 Code-Group Encoding and Injection
          2. 9.3.12.1.2 Scrambler
          3. 9.3.12.1.3 NRZ to NRZI Encoder
          4. 9.3.12.1.4 Binary to MLT-3 Converter
        2. 9.3.12.2 100BASE-TX Receiver
      13. 9.3.13 10BASE-Te
        1. 9.3.13.1 Squelch
        2. 9.3.13.2 Normal Link Pulse Detection and Generation
        3. 9.3.13.3 Jabber
        4. 9.3.13.4 Active Link Polarity Detection and Correction
      14. 9.3.14 Loopback Modes
        1. 9.3.14.1 Near-end Loopback
        2. 9.3.14.2 MII Loopback
        3. 9.3.14.3 PCS Loopback
        4. 9.3.14.4 Digital Loopback
        5. 9.3.14.5 Analog Loopback
        6. 9.3.14.6 Far-End (Reverse) Loopback
      15. 9.3.15 BIST Configurations
      16. 9.3.16 Cable Diagnostics
        1. 9.3.16.1 Time Domain Reflectometry (TDR)
        2. 9.3.16.2 Fast Link-Drop Functionality
      17. 9.3.17 LED and GPIO Configuration
    4. 9.4 Programming
      1. 9.4.1 Hardware Bootstraps Configuration
        1. 9.4.1.1 DP83826 Bootstrap Configurations (ENHANCED Mode)
          1. 9.4.1.1.1 Bootstraps for PHY Address
        2. 9.4.1.2 DP83826 Strap Configuration (BASIC Mode)
          1. 9.4.1.2.1 Bootstraps for PHY Address
    5. 9.5 Register Maps
      1. 9.5.1 DP83826 Registers
  11. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Applications
      1. 10.2.1 Twisted-Pair Interface (TPI) Network Circuit
      2. 10.2.2 Transformer Recommendations
      3. 10.2.3 Capacitive DC Blocking
      4. 10.2.4 Design Requirements
        1. 10.2.4.1 Clock Requirements
          1. 10.2.4.1.1 Oscillator
          2. 10.2.4.1.2 Crystal
      5. 10.2.5 Detailed Design Procedure
        1. 10.2.5.1 MII Layout Guidelines
        2. 10.2.5.2 RMII Layout Guidelines
        3. 10.2.5.3 MDI Layout Guidelines
      6. 10.2.6 Application Curves
  12. 11Power Supply Recommendations
  13. 12Layout
    1. 12.1 Layout Guidelines
      1. 12.1.1 Signal Traces
      2. 12.1.2 Return Path
      3. 12.1.3 Transformer Layout
      4. 12.1.4 Metal Pour
      5. 12.1.5 PCB Layer Stacking
        1. 12.1.5.1 Layout Example
  14. 13Device and Documentation Support
    1. 13.1 Related Documentation
    2. 13.2 Receiving Notification of Documentation Updates
    3. 13.3 Support Resources
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  15. 14Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information
9.3.12.1.2 Scrambler

The scrambler is required to control the radiated emissions at the media connector and on the twisted-pair cable. By scrambling the data, the total energy launched onto the cable is randomly distributed over a wide frequency range. Without the scrambler, energy levels at the MDI and on the cable could peak beyond FCC limitations at frequencies related to repeating 5B sequences (that is, continuous transmission of IDLEs).

The scrambler is configured as a closed loop linear feedback shift register (LFSR) with an 11-bit polynomial. The output of the closed loop LFSR is X-ORd with the serial NRZ data from the code-group encoder. The result is a scrambled data stream with sufficient randomization to decrease radiated emissions at certain frequencies by as much as 20 dB.