SNAU288 December   2023 LMX1906-SP

 

  1.   1
  2.   Description
  3.   Features
  4.   Applications
  5.   5
  6. 1Evaluation Module Overview
    1. 1.1 Introduction
    2. 1.2 Kit Contents
    3. 1.3 Specification
    4. 1.4 Device Information
  7. 2Hardware
    1. 2.1 Setup
      1. 2.1.1 Evaluation Setup Requirement
      2. 2.1.2 Connection Diagram
        1. 2.1.2.1 How to Enable Full SPI Control
      3. 2.1.3 Power Requirements
      4. 2.1.4 Pin Mode Strapping
      5. 2.1.5 Reference Clock
        1. 2.1.5.1 Output Connections
        2. 2.1.5.2 Header Information
        3. 2.1.5.3 Default Configuration
        4. 2.1.5.4 How to Generate SYSREF
        5. 2.1.5.5 Multiplier Mode Example
        6. 2.1.5.6 Divider Mode Example
        7. 2.1.5.7 Hybrid Mode: SPI and Pin Mode
  8. 3Software
    1. 3.1 Software Installation
    2. 3.2 Software Description
    3. 3.3 USB2ANY Interface
  9. 4Implementation Results
    1. 4.1 Buffer, Divider, and Multiplier Modes
    2. 4.2 SYSREF Generation
    3. 4.3 SYSREF Delay Generators
  10. 5Hardware Design Files
    1. 5.1 Schematic
    2. 5.2 PCB Layout
      1. 5.2.1 PCB Layer Stack-Up
    3. 5.3 Bill of Materials
  11. 6Additional Information
    1. 6.1 Troubleshooting Guide
      1. 6.1.1 General Guidance
      2. 6.1.2 If Output Is Not Seen on CLKOUT
      3. 6.1.3 If Device Features Are Not Active
      4. 6.1.4 If Multiplier Frequency Is Not Accurate
      5. 6.1.5 If Divider Frequency Is Not Accurate
      6. 6.1.6 If SYSREF Is Not Observed
    2. 6.2 Trademarks

2.1.5.1 Output Connections

All CLKOUT connections are AC-coupled at the LMX1906-SP EVM and can be connected directly to RF instruments with 0VDC requirements; an additional DC block is not required. The unused CLKOUT SMA connector must be terminated with a 50-Ω load, or a differential connection can be used if a balun with the best frequency range is available.

Recommended oscilloscope connections include one CLKOUT and one SYSREF output from the same channel, as well as the one LOGICLK and one LOGISYS output.

Other unused CLKOUT SMA connectors must be terminated with 50-Ω single-ended or 100-Ω differential load, or alternately must be disabled in software, to minimize unterminated output effects on performance.