SNAA421 November   2025 LMK05318B , LMK5B12204 , LMK5B33216 , LMK5B33414 , LMK5C33216A , LMK5C33414A

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Start Here: Using TICS Pro for Configuration and Readback
    1. 1.1 TICS Pro Status Page
    2. 1.2 TICS Pro Default Setting
  5. 2Debug Procedure: From Device Start-Up to Locked Output State
    1. 2.1 Is the APLL Reference Valid?
      1. 2.1.1 Check Status of APLL Reference
      2. 2.1.2 Debug APLL Reference
    2. 2.2 Is the APLL Locked?
      1. 2.2.1 Check Status of APLL Lock
      2. 2.2.2 Debug APLL Lock
    3. 2.3 Is the DPLL Reference Valid?
      1. 2.3.1 Check Status of DPLL Reference Validation
      2. 2.3.2 Debug DPLL Reference Validation
    4. 2.4 Is the DPLL Selecting a Reference?
      1. 2.4.1 Check Status of DPLL Reference Selection
      2. 2.4.2 Debug DPLL Reference Selection
    5. 2.5 Is the DPLL Frequency Locked?
      1. 2.5.1 Check Status of DPLL Frequency Lock
      2. 2.5.2 Debug DPLL Frequency Lock
    6. 2.6 Is the DPLL Phase Locked?
      1. 2.6.1 Check Status of DPLL Phase Lock
      2. 2.6.2 Debug DPLL Phase Lock
  6. 3Summary
  7. 4References

Abstract

Network synchronizers use a combination of a digital and analog phase-locked loops (DPLL and APLL) to provide input-to-output synchronization, output clock generation, and jitter cleaning capabilities. With the DPLL, the network synchronizer can support additional features such as hitless switching, holdover, digitally-controlled oscillators (DCO), and jitter cleaning for close-in phase noise (less than 1kHz offsets). The addition of a DPLL adds complexity and can result in more debug steps than a simple clock generator.

The purpose of the application note is to provide a step-by-step guide on how to debug network synchronizers, specifically on how to achieve DPLL phase lock, which is a common debug inquiry. The devices applicable to the application note are listed in Table 1-1. When referring to all of the devices listed, the application note uses the term LMK device for a generalized name. When referring to a particular device grouping, the application note uses the family name.

Table 1-1 Network Synchronizer Device Families
DEVICE FAMILY NAMEDEVICE PART NUMBERS IN FAMILY
LMK05318(1)LMK05318
LMK05318BLMK05318B, LMK05318B-Q1, LMK5B12204
LMK5C(1)LMK5C33216
LMK5BLMK5B33216, LMK5B33414, LMK5B12212
LMK5CALMK5C33216A, LMK5C33414A, LMK5C33216AS1, LMK5C33414AS1, LMK5C22212A, LMK5C23208A
(1) Not recommended for new designs.