SNAU246A June   2020  – January 2021 LMX2820

 

  1. 1Trademarks
  2. 2LMX2820EVM Evaluation Module
    1. 2.1 Evaluation Module Contents
    2. 2.2 Evaluation Setup Requirement
    3. 2.3 Resources
  3. 3Setup
    1. 3.1 Connection Diagram
    2. 3.2 Power Supply
    3. 3.3 Reference Clock
    4. 3.4 RF Output
    5. 3.5 Programming
    6. 3.6 Evaluation Software
  4. 4Typical Measurement
    1. 4.1 Default Configuration
      1. 4.1.1 Loop Filter
      2. 4.1.2 Typical Output
    2. 4.2 Additional Tests
      1. 4.2.1 SYSREF Example
      2. 4.2.2 Offset Mixing With PFDIN Pin
      3. 4.2.3 External VCO Mode
      4. 4.2.4 Register Readback
  5. 5Schematic
  6. 6PCB Layout and Layer Stack-Up
    1. 6.1 PCB Layer Stack-Up
    2. 6.2 PCB Layout
  7. 7Bill of Materials
  8. 8Troubleshooting Guide
    1.     A Using Different Reference Clock
      1.      B USB2ANY Firmware Upgrade
        1.       C Revision History

8 Troubleshooting Guide

If the EVM does not work as expected, use Figure 8-1 to identify potential root causes. Consider the following:

  • Do not make modifications to the EVM or change the default settings until AFTER it is verified to be working.
  • Register read back requires the correct software setup. See Section 4.2.4 for details.
  • The POR current of the LMX2820EVM is approximately 220 mA.
  • The power-down current of the LMX2820EVM is approximately 10 mA.

GUID-532226C8-B799-4AFB-BAFB-559EF0135875-low.gifFigure 8-1 Troubleshooting Guide