SNAU293 May   2024 LMX1860-SEP

 

  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
      3. 2.1.3  How to Enable Full SPI Control
      4. 2.1.4  Power Requirements
      5. 2.1.5  Pin Mode Strapping
      6. 2.1.6  Reference Clock
      7. 2.1.7  Output Connections
      8. 2.1.8  Header Information
      9. 2.1.9  Default Configuration
      10. 2.1.10 How to Generate SYSREF
      11. 2.1.11 Multiplier Mode Example
      12. 2.1.12 Divider Mode Example
      13. 2.1.13 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
    3. 5.3 PCB Layer Stack-Up
    4. 5.4 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

6.1.4 If Multiplier Frequency Is Not Accurate

The multiplier requires several registers to be programmed, and a calibration must be triggered by R0 write whenever the frequency changes or when the multiplier is first selected.

  • Confirm the frequency input and output range for the device is appropriate. The GUI indicates if frequencies are out of range by highlighting the input or output box with the range violation.
  • Make sure that all registers have been loaded (Ctrl+L). This also calibrates the multiplier.
  • Try toggling the RESET bit on the User Controls page before loading all registers again (Ctrl+L).
  • Refer to the data sheet to make sure a valid multiplier value is being used for the corresponding input frequency.