SNAS859 March   2024 LMK05318B-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
    1. 4.1 Device Start-Up Modes
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information: 4-Layer JEDEC Standard PCB
    5. 5.5 Thermal Information: 10-Layer Custom PCB
    6. 5.6 Electrical Characteristics
    7. 5.7 Timing Diagrams
    8. 5.8 Typical Characteristics
  7. 6 Parameter Measurement Information
    1. 6.1 Output Clock Test Configurations
  8. 7 Detailed Description
    1. 7.1 Overview
      1. 7.1.1 ITU-T G.8262 (SyncE) Standards Compliance
    2. 7.2 Functional Block Diagram
      1. 7.2.1 PLL Architecture Overview
      2. 7.2.2 DPLL Mode
      3. 7.2.3 APLL-Only Mode
    3. 7.3 Feature Description
      1. 7.3.1  Oscillator Input (XO_P/N)
      2. 7.3.2  Reference Inputs (PRIREF_P/N and SECREF_P/N)
      3. 7.3.3  Clock Input Interfacing and Termination
      4. 7.3.4  Reference Input Mux Selection
        1. 7.3.4.1 Automatic Input Selection
        2. 7.3.4.2 Manual Input Selection
      5. 7.3.5  Hitless Switching
        1. 7.3.5.1 Hitless Switching With 1-PPS Inputs
      6. 7.3.6  Gapped Clock Support on Reference Inputs
      7. 7.3.7  Input Clock and PLL Monitoring, Status, and Interrupts
        1. 7.3.7.1 XO Input Monitoring
        2. 7.3.7.2 Reference Input Monitoring
          1. 7.3.7.2.1 Reference Validation Timer
          2. 7.3.7.2.2 Amplitude Monitor
          3. 7.3.7.2.3 Frequency Monitoring
          4. 7.3.7.2.4 Missing Pulse Monitor (Late Detect)
          5. 7.3.7.2.5 Runt Pulse Monitor (Early Detect)
          6. 7.3.7.2.6 Phase Valid Monitor for 1-PPS Inputs
        3. 7.3.7.3 PLL Lock Detectors
        4. 7.3.7.4 Tuning Word History
        5. 7.3.7.5 Status Outputs
        6. 7.3.7.6 Interrupt
      8. 7.3.8  PLL Relationships
        1. 7.3.8.1  PLL Frequency Relationships
        2. 7.3.8.2  Analog PLLs (APLL1, APLL2)
        3. 7.3.8.3  APLL Reference Paths
          1. 7.3.8.3.1 APLL XO Doubler
          2. 7.3.8.3.2 APLL1 XO Reference (R) Divider
          3. 7.3.8.3.3 APLL2 Reference (R) Dividers
        4. 7.3.8.4  APLL Phase Frequency Detector (PFD) and Charge Pump
        5. 7.3.8.5  APLL Feedback Divider Paths
          1. 7.3.8.5.1 APLL1 N Divider With SDM
          2. 7.3.8.5.2 APLL2 N Divider With SDM
        6. 7.3.8.6  APLL Loop Filters (LF1, LF2)
        7. 7.3.8.7  APLL Voltage Controlled Oscillators (VCO1, VCO2)
          1. 7.3.8.7.1 VCO Calibration
        8. 7.3.8.8  APLL VCO Clock Distribution Paths (P1, P2)
        9. 7.3.8.9  DPLL Reference (R) Divider Paths
        10. 7.3.8.10 DPLL Time-to-Digital Converter (TDC)
        11. 7.3.8.11 DPLL Loop Filter (DLF)
        12. 7.3.8.12 DPLL Feedback (FB) Divider Path
      9. 7.3.9  Output Clock Distribution
      10. 7.3.10 Output Channel Muxes
      11. 7.3.11 Output Dividers (OD)
      12. 7.3.12 Clock Outputs (OUTx_P/N)
        1. 7.3.12.1 AC-Differential Output (AC-DIFF)
        2. 7.3.12.2 HCSL Output
        3. 7.3.12.3 1.8V LVCMOS Output
        4. 7.3.12.4 Output Auto-Mute During LOL
      13. 7.3.13 Glitchless Output Clock Start-Up
      14. 7.3.14 Clock Output Interfacing and Termination
      15. 7.3.15 Output Synchronization (SYNC)
    4. 7.4 Device Functional Modes
      1. 7.4.1 Device Start-Up Modes
        1. 7.4.1.1 EEPROM Mode
      2. 7.4.2 PLL Operating Modes
        1. 7.4.2.1 Free-Run Mode
        2. 7.4.2.2 Lock Acquisition
        3. 7.4.2.3 Locked Mode
        4. 7.4.2.4 Holdover Mode
      3. 7.4.3 PLL Start-Up Sequence
      4. 7.4.4 Digitally-Controlled Oscillator (DCO) Mode
        1. 7.4.4.1 DCO Frequency Step Size
        2. 7.4.4.2 DCO Direct-Write Mode
    5. 7.5 Programming
      1. 7.5.1 Interface and Control
      2. 7.5.2 I2C Serial Communication
        1. 7.5.2.1 I2C Block Register Transfers
      3. 7.5.3 SPI Serial Communication
        1. 7.5.3.1 SPI Block Register Transfer
      4. 7.5.4 Register Map and EEPROM Map Generation
      5. 7.5.5 General Register Programming Sequence
      6. 7.5.6 EEPROM Programming Flow
        1. 7.5.6.1 EEPROM Programming Using Method #1 (Register Commit)
          1. 7.5.6.1.1 Write SRAM Using Register Commit
          2. 7.5.6.1.2 Program EEPROM
        2. 7.5.6.2 EEPROM Programming Using Method #2 (Direct Writes)
          1. 7.5.6.2.1 Write SRAM Using Direct Writes
          2. 7.5.6.2.2 User-Programmable Fields In EEPROM
      7. 7.5.7 Read SRAM
      8. 7.5.8 Read EEPROM
      9. 7.5.9 EEPROM Start-Up Mode Default Configuration
  9. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Device Start-Up Sequence
      2. 8.1.2 Power Down (PDN) Pin
      3. 8.1.3 Power Rail Sequencing, Power Supply Ramp Rate, and Mixing Supply Domains
        1. 8.1.3.1 Mixing Supplies
        2. 8.1.3.2 Power-On Reset (POR) Circuit
        3. 8.1.3.3 Powering Up From a Single-Supply Rail
        4. 8.1.3.4 Power Up From Split-Supply Rails
        5. 8.1.3.5 Non-Monotonic or Slow Power-Up Supply Ramp
      4. 8.1.4 Slow or Delayed XO Start-Up
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
    3. 8.3 Best Design Practices
    4. 8.4 Power Supply Recommendations
      1. 8.4.1 Power Supply Bypassing
      2. 8.4.2 Device Current and Power Consumption
        1. 8.4.2.1 Current Consumption Calculations
        2. 8.4.2.2 Power Consumption Calculations
        3. 8.4.2.3 Example
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
      2. 8.5.2 Layout Example
      3. 8.5.3 Thermal Reliability
        1. 8.5.3.1 Support for PCB Temperature up to 105°C
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 TICS Pro
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 Receiving Notification of Documentation Updates
    4. 9.4 Support Resources
    5. 9.5 Trademarks
    6. 9.6 Electrostatic Discharge Caution
    7. 9.7 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • RGZ|48
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.4.2.4 Holdover Mode

When a loss-of-reference (LOR) condition is detected and no valid input is available, the PLL1 channel enters holdover mode. If the tuning word history is valid, the initial output frequency accuracy upon entry into holdover is pulled to the computed average frequency accuracy just prior to the loss of reference. If history is not valid (no history exists) and the DPLL_HLDOVR_MODE bit is 0, the holdover frequency accuracy is determined by the free-run tuning word register (user programmable). Otherwise, if history is not valid and DPLL_HLDOVR_MODE is 1, the DPLL holds the last digital loop filter output control value (which is not tuning word history).

If history is valid, the initial holdover frequency accuracy depends on the DPLL loop bandwidth and the elapsed time used for historical averaging. See Tuning Word History for more information. In general, the longer the historical average time, the more accurate the initial holdover frequency assuming the 0ppm reference clock (XO input) is drift-free. The stability of the XO reference clock determines the long-term stability and accuracy of the holdover output frequency. Upon entry into holdover, the LOPL flag is asserted (LOPL → 1). The LOFL flag is not asserted, however, as long as the holdover frequency accuracy does not drift beyond of the programmed loss-of-frequency-lock threshold. When a valid input becomes available for selection, the PLL1 channel exits holdover mode and automatically phase lock with the new input clock without any output glitches.