SNLS341C March   2011  – March 2015 DP83848Q-Q1

PRODUCTION DATA.  

  1. 1 Device Overview
    1. 1.1 Features
    2. 1.2 Applications
    3. 1.3 Description
    4. 1.4 Functional Block Diagram
  2. 2 Revision History
  3. 3 Pin Configuration and Functions
    1. 3.1  Pin Layout
    2. 3.2  Package Pin Assignments
    3. 3.3  Serial Management Interface
    4. 3.4  MAC Data Interface
    5. 3.5  Clock Interface
    6. 3.6  LED Interface
    7. 3.7  RESET
    8. 3.8  Strap Options
    9. 3.9  10 Mb/s and 100 Mb/s PMD Interface
    10. 3.10 Special Connections
    11. 3.11 Power Supply Pins
  4. 4 Specifications
    1. 4.1 Absolute Maximum Ratings
    2. 4.2 ESD Ratings
    3. 4.3 Recommended Operating Conditions
    4. 4.4 Thermal Information
    5. 4.5 Electrical Characteristics: DC
    6. 4.6 Electrical Characteristics: AC
  5. 5 Detailed Description
    1. 5.1 Overview
    2. 5.2 Functional Block Diagram
    3. 5.3 Feature Description
      1. 5.3.1 Auto-Negotiation
        1. 5.3.1.1 Auto-Negotiation Pin Control
        2. 5.3.1.2 Auto-Negotiation Register Control
        3. 5.3.1.3 Auto-Negotiation Parallel Detection
        4. 5.3.1.4 Auto-Negotiation Restart
        5. 5.3.1.5 Enabling Auto-Negotiation via Software
        6. 5.3.1.6 Auto-Negotiation Complete Time
      2. 5.3.2 Auto-MDIX
      3. 5.3.3 LED Interface
        1. 5.3.3.1 LEDs
        2. 5.3.3.2 LED Direct Control
      4. 5.3.4 Internal Loopback
      5. 5.3.5 BIST
      6. 5.3.6 Energy Detect Mode
    4. 5.4 Device Functional Modes
      1. 5.4.1 MII Interface
        1. 5.4.1.1 Nibble-wide MII Data Interface
        2. 5.4.1.2 Collision Detect
        3. 5.4.1.3 Carrier Sense
      2. 5.4.2 Reduced MII Interface
      3. 5.4.3 802.3u MII Serial Management Interface
        1. 5.4.3.1 Serial Management Register Access
        2. 5.4.3.2 Serial Management Access Protocol
        3. 5.4.3.3 Serial Management Preamble Suppression
      4. 5.4.4 PHY Address
        1. 5.4.4.1 MII Isolate Mode
      5. 5.4.5 Half Duplex vs. Full Duplex
      6. 5.4.6 Reset Operation
        1. 5.4.6.1 Hardware Reset
        2. 5.4.6.2 Software Reset
    5. 5.5 Programming
      1. 5.5.1 Architecture
        1. 5.5.1.1 100BASE-TX Transmitter
          1. 5.5.1.1.1 Code-Group Encoding and Injection
          2. 5.5.1.1.2 Scrambler
          3. 5.5.1.1.3 NRZ to NRZI Encoder
          4. 5.5.1.1.4 Binary to MLT-3 Convertor
        2. 5.5.1.2 100BASE-TX Receiver
          1. 5.5.1.2.1  Analog Front End
          2. 5.5.1.2.2  Digital Signal Processor
            1. 5.5.1.2.2.1 Digital Adaptive Equalization and Gain Control
            2. 5.5.1.2.2.2 Base Line Wander Compensation
          3. 5.5.1.2.3  Signal Detect
          4. 5.5.1.2.4  MLT-3 to NRZI Decoder
          5. 5.5.1.2.5  NRZI to NRZ
          6. 5.5.1.2.6  Serial to Parallel
          7. 5.5.1.2.7  Descrambler
          8. 5.5.1.2.8  Code-group Alignment
          9. 5.5.1.2.9  4B/5B Decoder
          10. 5.5.1.2.10 100BASE-TX Link Integrity Monitor
          11. 5.5.1.2.11 Bad SSD Detection
        3. 5.5.1.3 10BASE-T Transceiver Module
          1. 5.5.1.3.1  Operational Modes
            1. 5.5.1.3.1.1 Half Duplex Mode
            2. 5.5.1.3.1.2 Full Duplex Mode
          2. 5.5.1.3.2  Smart Squelch
          3. 5.5.1.3.3  Collision Detection and SQE
          4. 5.5.1.3.4  Carrier Sense
          5. 5.5.1.3.5  Normal Link Pulse Detection and Generation
          6. 5.5.1.3.6  Jabber Function
          7. 5.5.1.3.7  Automatic Link Polarity Detection and Correction
          8. 5.5.1.3.8  Transmit and Receive Filtering
          9. 5.5.1.3.9  Transmitter
          10. 5.5.1.3.10 Receiver
    6. 5.6 Memory
      1. 5.6.1 Register Definition
        1. 5.6.1.1 Basic Mode Control Register (BMCR)
        2. 5.6.1.2 Basic Mode Status Register (BMSR)
        3. 5.6.1.3 PHY Identifier Register #1 (PHYIDR1)
        4. 5.6.1.4 PHY Identifier Register #2 (PHYIDR2)
        5. 5.6.1.5 Auto-Negotiation Advertisement Register (ANAR)
        6. 5.6.1.6 Auto-Negotiation Link Partner Ability Register (ANLPAR) (BASE Page)
        7. 5.6.1.7 Auto-Negotiation Link Partner Ability Register (ANLPAR) (Next Page)
        8. 5.6.1.8 Auto-Negotiate Expansion Register (ANER)
        9. 5.6.1.9 Auto-Negotiation Next Page Transmit Register (ANNPTR)
      2. 5.6.2 Extended Registers
        1. 5.6.2.1  PHY Status Register (PHYSTS)
        2. 5.6.2.2  False Carrier Sense Counter Register (FCSCR)
        3. 5.6.2.3  Receiver Error Counter Register (RECR)
        4. 5.6.2.4  100 Mb/s PCS Configuration and Status Register (PCSR)
        5. 5.6.2.5  RMII and Bypass Register (RBR)
        6. 5.6.2.6  LED Direct Control Register (LEDCR)
        7. 5.6.2.7  PHY Control Register (PHYCR)
        8. 5.6.2.8  10 Base-T Status/Control Register (10BTSCR)
        9. 5.6.2.9  CD Test and BIST Extensions Register (CDCTRL1)
        10. 5.6.2.10 Energy Detect Control (EDCR)
  6. 6 Application and Implementation
    1. 6.1 Application Information
    2. 6.2 Typical Application
      1. 6.2.1 Design Requirements
        1. 6.2.1.1 TPI Network Circuit
        2. 6.2.1.2 Clock IN (X1) Requirements
        3. 6.2.1.3 Power Feedback Circuit
        4. 6.2.1.4 Magnetics
      2. 6.2.2 Detailed Design Procedure
        1. 6.2.2.1 MAC Interface (MII/RMII)
        2. 6.2.2.2 Termination Requirement
        3. 6.2.2.3 Recommended Maximum Trace Length
        4. 6.2.2.4 Calculating Impedance
      3. 6.2.3 Application Curve
  7. 7 Power Supply Recommendations
  8. 8 Layout
    1. 8.1 Layout Guidelines
      1. 8.1.1 PCB Layout Considerations
      2. 8.1.2 PCB Layer Stacking
    2. 8.2 Layout Example
  9. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Trademarks
    3. 9.3 Electrostatic Discharge Caution
    4. 9.4 Glossary
  10. 10Mechanical, Packaging, and Orderable Information

Package Options

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

8 Layout

8.1 Layout Guidelines

8.1.1 PCB Layout Considerations

Place the 49.9-Ω,1% resistors, and 0.1-μF decoupling capacitor, near the PHYTER TD± and RD± pins and via directly to the Vdd plane. Stubs should be avoided on all signal traces, especially the differential signal pairs. See Figure 8-1. Within the pairs (for example, TD+ and TD–) the trace lengths should be run parallel to each other and matched in length. Matched lengths minimize delay differences, avoiding an increase in common mode noise and increased EMI. See Figure 8-1.

DP83848Q-Q1 20191117.gifFigure 8-1 Differential Signal Pair – Stubs

Ideally there should be no crossover or via on the signal paths. Vias present impedance discontinuities and should be minimized. Route an entire trace pair on a single layer if possible. PCB trace lengths should be kept as short as possible. Signal traces should not be run such that they cross a plane split. See Figure 8-2. A signal crossing a plane split may cause unpredictable return path currents and would likely impact signal quality as well, potentially creating EMI problems.

DP83848Q-Q1 20191104.gifFigure 8-2 Differential Signal Pair-Plane Crossing

MDI signal traces should have 50 Ω to ground or 100-Ω differential controlled impedance. Many tools are available online to calculate this.

8.1.2 PCB Layer Stacking

To meet signal integrity and performance requirements, at minimum a four layer PCB is recommended for implementing PHYTER components in end user systems. The following layer stack-ups are recommended for four, six, and eight-layer boards, although other options are possible.

DP83848Q-Q1 20191115.gifFigure 8-3 PCB Stripline Layer Stacking

Within a PCB it may be desirable to run traces using different methods, microstrip vs. stripline, depending on the location of the signal on the PCB. For example, it may be desirable to change layer stacking where an isolated chassis ground plane is used. Figure 8-4 illustrates alternative PCB stacking options.

DP83848Q-Q1 20191116.gifFigure 8-4 Alternative PCB Stripline Layer Stacking

8.2 Layout Example

DP83848Q-Q1 30067012.gifFigure 8-5 Layout Example