SNLS544B September   2016  – October 2019 DS280BR820

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Simplified Schematic
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Electrical Characteristics – Serial Management Bus Interface
    7. 6.7 Timing Requirements – Serial Management Bus Interface
    8. 6.8 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Device Data Path Operation
      2. 7.3.2 AC-Coupled Receiver Inputs
      3. 7.3.3 Signal Detect
      4. 7.3.4 2-Stage CTLE
      5. 7.3.5 Driver DC Gain Control
      6. 7.3.6 FIR Filter (Limiting Mode)
      7. 7.3.7 Configurable SMBus Address
    4. 7.4 Device Functional Modes
      1. 7.4.1 SMBus Slave Mode Configuration
      2. 7.4.2 SMBus Master Mode Configuration (EEPROM Self Load)
    5. 7.5 Programming
      1. 7.5.1 Transfer of Data with the SMBus Interface
    6. 7.6 Register Maps
      1. 7.6.1 Register Types: Global, Shared, and Channel
      2. 7.6.2 Global Registers: Channel Selection and ID Information
        1. Table 2. Global Register Map
      3. 7.6.3 Shared Registers
        1. Table 3. Shared Register Map
      4. 7.6.4 Channel Registers
        1. Table 4. Channel Register Map
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Backplane and Mid-Plane Reach Extension
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
      2. 8.2.2 Front-Port Applications
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
        1. 8.2.3.1 Pattern Generator Characteristics
        2. 8.2.3.2 Equalizing Moderate Pre-Channel Loss
        3. 8.2.3.3 Equalizing High Pre-Channel Loss
        4. 8.2.3.4 Equalizing High Pre-Channel Loss and Moderate Post-Channel Loss
        5. 8.2.3.5 Output in FIR Limiting Mode with 16T Pattern
    3. 8.3 Initialization Set Up
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Examples
      1. 10.2.1 Stripline Example
      2. 10.2.2 Microstrip Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary

Package Options

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

3 Description

The DS280BR820 is an extremely low-power, high-performance eight-channel linear equalizer supporting multi-rate, multi-protocol interfaces up to 28 Gbps. It is used to extend the reach and improve the robustness of high-speed serial links for backplane, front-port, and chip-to-chip applications.

The linear nature of the DS280BR820’s equalization preserves the transmit signal characteristics, thereby allowing the host and link partner ASICs to freely negotiate transmit equalizer coefficients (100G-CR4/KR4). This transparency to the link training protocol facilitates system-level interoperability with minimal effect on the latency. Each channel operates independently, which allows the DS280BR820 to support individual lane Forward Error Correction (FEC) pass-through.

The DS280BR820's small package dimensions, optimized high-speed signal escape, and the pin-compatible Retimer portfolio make the DS280BR820 ideal for high-density backplane applications. Simplified equalization control, low power consumption, and ultra-low additive jitter make it suitable for front-port interfaces such as 100G-SR4/LR4/CR4. The small 8-mm x 13-mm footprint easily fits behind numerous standard front-port connectors like QSFP, SFP, CFP2, CFP4, and CDFP without the need for a heat sink.

Integrated AC coupling capacitors (RX side) eliminate the need for external capacitors on the PCB. The DS280BR820 has a single power supply and minimal need for external components. These features reduce PCB routing complexity and bill of materials (BOM) cost.

A pin-compatible Retimer device is available for longer reach applications.

The DS280BR820 can be configured either through the SMBus or through an external EEPROM. Up to 16 devices can share a single EEPROM.

Device Information (1)

PART NUMBER PACKAGE BODY SIZE (NOM)
DS280BR820 nFBGA (135) 8.0 mm x 13.0 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Simplified Schematic

DS280BR820 schematic_page1_externalCaps.gif