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

6.1.5 If Divider Frequency Is Not Accurate

The main clock output divider is designed with the expectation that the register settings is loaded only once after POR. In some cases, the main clock output divider does not always cleanly transition between divide values if the value is changed after POR. To change the divider value, toggle the RESET bit on the User Controls page and load all registers again (Ctrl+L).

  • Refer to the data sheet to make sure a valid divider ratio value is being used for corresponding input frequency.
  • A LOW to HIGH transition on the CAL header resets divider in pin mode.
    • This can also be accomplished using IO expander in hybrid mode.