SNAS801B June   2020  – June 2021 LMK05318B

PRODUCTION DATA  

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Description (continued)
  6. Pin Configuration and Functions
    1. 6.1 Device Start-Up Modes
  7. Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information: 4-Layer JEDEC Standard PCB
    5. 7.5 Thermal Information: 10-Layer Custom PCB
    6. 7.6 Electrical Characteristics
    7. 7.7 Timing Diagrams
    8. 7.8 Typical Characteristics
  8. Parameter Measurement Information
    1. 8.1 Output Clock Test Configurations
  9. Detailed Description
    1. 9.1 Overview
      1. 9.1.1 ITU-T G.8262 (SyncE) Standards Compliance
    2. 9.2 Functional Block Diagram
      1. 9.2.1 PLL Architecture Overview
      2. 9.2.2 DPLL Mode
      3. 9.2.3 APLL-Only Mode
    3. 9.3 Feature Description
      1. 9.3.1  Oscillator Input (XO_P/N)
      2. 9.3.2  Reference Inputs (PRIREF_P/N and SECREF_P/N)
        1. 9.3.2.1 Programmable Input Hysteresis
      3. 9.3.3  Clock Input Interfacing and Termination
      4. 9.3.4  Reference Input Mux Selection
        1. 9.3.4.1 Automatic Input Selection
        2. 9.3.4.2 Manual Input Selection
      5. 9.3.5  Hitless Switching
        1. 9.3.5.1 Hitless Switching With 1-PPS Inputs
      6. 9.3.6  Gapped Clock Support on Reference Inputs
      7. 9.3.7  Input Clock and PLL Monitoring, Status, and Interrupts
        1. 9.3.7.1 XO Input Monitoring
        2. 9.3.7.2 Reference Input Monitoring
          1. 9.3.7.2.1 Reference Validation Timer
          2. 9.3.7.2.2 Amplitude Monitor
          3. 9.3.7.2.3 Frequency Monitoring
          4. 9.3.7.2.4 Missing Pulse Monitor (Late Detect)
          5. 9.3.7.2.5 Runt Pulse Monitor (Early Detect)
          6. 9.3.7.2.6 Phase Valid Monitor for 1-PPS Inputs
        3. 9.3.7.3 PLL Lock Detectors
        4. 9.3.7.4 Tuning Word History
        5. 9.3.7.5 Status Outputs
        6. 9.3.7.6 Interrupt
      8. 9.3.8  PLL Relationships
        1. 9.3.8.1  PLL Frequency Relationships
        2. 9.3.8.2  Analog PLLs (APLL1, APLL2)
        3. 9.3.8.3  APLL Reference Paths
          1. 9.3.8.3.1 APLL XO Doubler
          2. 9.3.8.3.2 APLL1 XO Reference (R) Divider
          3. 9.3.8.3.3 APLL2 Reference (R) Dividers
        4. 9.3.8.4  APLL Phase Frequency Detector (PFD) and Charge Pump
        5. 9.3.8.5  APLL Feedback Divider Paths
          1. 9.3.8.5.1 APLL1 N Divider With SDM
          2. 9.3.8.5.2 APLL2 N Divider With SDM
        6. 9.3.8.6  APLL Loop Filters (LF1, LF2)
        7. 9.3.8.7  APLL Voltage Controlled Oscillators (VCO1, VCO2)
          1. 9.3.8.7.1 VCO Calibration
        8. 9.3.8.8  APLL VCO Clock Distribution Paths (P1, P2)
        9. 9.3.8.9  DPLL Reference (R) Divider Paths
        10. 9.3.8.10 DPLL Time-to-Digital Converter (TDC)
        11. 9.3.8.11 DPLL Loop Filter (DLF)
        12. 9.3.8.12 DPLL Feedback (FB) Divider Path
      9. 9.3.9  Output Clock Distribution
      10. 9.3.10 Output Channel Muxes
      11. 9.3.11 Output Dividers (OD)
      12. 9.3.12 Clock Outputs (OUTx_P/N)
        1. 9.3.12.1 AC-Differential Output (AC-DIFF)
        2. 9.3.12.2 HCSL Output
        3. 9.3.12.3 1.8-V LVCMOS Output
        4. 9.3.12.4 Output Auto-Mute During LOL
      13. 9.3.13 Glitchless Output Clock Start-Up
      14. 9.3.14 Clock Output Interfacing and Termination
      15. 9.3.15 Output Synchronization (SYNC)
      16. 9.3.16 Zero-Delay Mode (ZDM) Synchronization for 1-PPS Input and Output
    4. 9.4 Device Functional Modes
      1. 9.4.1 Device Start-Up Modes
        1. 9.4.1.1 EEPROM Mode
        2. 9.4.1.2 ROM Mode
      2. 9.4.2 PLL Operating Modes
        1. 9.4.2.1 Free-Run Mode
        2. 9.4.2.2 Lock Acquisition
        3. 9.4.2.3 Locked Mode
        4. 9.4.2.4 Holdover Mode
      3. 9.4.3 PLL Start-Up Sequence
      4. 9.4.4 Digitally-Controlled Oscillator (DCO) Mode
        1. 9.4.4.1 DCO Frequency Step Size
        2. 9.4.4.2 DCO Direct-Write Mode
      5. 9.4.5 Zero-Delay Mode Synchronization
    5. 9.5 Programming
      1. 9.5.1 Interface and Control
      2. 9.5.2 I2C Serial Interface
        1. 9.5.2.1 I2C Block Register Transfers
      3. 9.5.3 SPI Serial Interface
        1. 9.5.3.1 SPI Block Register Transfer
      4. 9.5.4 Register Map and EEPROM Map Generation
      5. 9.5.5 General Register Programming Sequence
      6. 9.5.6 EEPROM Programming Flow
        1. 9.5.6.1 EEPROM Programming Using Method #1 (Register Commit)
          1. 9.5.6.1.1 Write SRAM Using Register Commit
          2. 9.5.6.1.2 Program EEPROM
        2. 9.5.6.2 EEPROM Programming Using Method #2 (Direct Writes)
          1. 9.5.6.2.1 Write SRAM Using Direct Writes
          2. 9.5.6.2.2 User-Programmable Fields In EEPROM
      7. 9.5.7 Read SRAM
      8. 9.5.8 Read EEPROM
      9. 9.5.9 EEPROM Start-Up Mode Default Configuration
  10. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 Device Start-Up Sequence
      2. 10.1.2 Power Down (PDN) Pin
      3. 10.1.3 Power Rail Sequencing, Power Supply Ramp Rate, and Mixing Supply Domains
        1. 10.1.3.1 Mixing Supplies
        2. 10.1.3.2 Power-On Reset (POR) Circuit
        3. 10.1.3.3 Powering Up From a Single-Supply Rail
        4. 10.1.3.4 Power Up From Split-Supply Rails
        5. 10.1.3.5 Non-Monotonic or Slow Power-Up Supply Ramp
      4. 10.1.4 Slow or Delayed XO Start-Up
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
      3. 10.2.3 Application Curves
    3. 10.3 Do's and Don'ts
  11. 11Power Supply Recommendations
    1. 11.1 Power Supply Bypassing
    2. 11.2 Device Current and Power Consumption
      1. 11.2.1 Current Consumption Calculations
      2. 11.2.2 Power Consumption Calculations
      3. 11.2.3 Example
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
    3. 12.3 Thermal Reliability
      1. 12.3.1 Support for PCB Temperature up to 105 °C
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 TICS Pro
      2. 13.1.2 Related Documentation
    2. 13.2 Receiving Notification of Documentation Updates
    3. 13.3 Support Resources
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

Overview

The LMK05318B has two reference inputs, one digital PLL (DPLL), two analog PLLs (APLLs) with integrated VCOs, and eight output clocks with a RMS phase jitter of 50-fs typical from APLL1 and 130-fs typical from APLL2. APLL1 uses an ultra-high performance BAW VCO (VCO1) with a very high quality factor, and thus has no dependency on the phase noise or frequency of the external oscillator (XO) input clock. This minimizes the overall solution cost and allows the use of an off-the-shelf XO, TCXO, or OCXO selected to meet the free-run and holdover frequency stability requirements of the application. APLL1 is cascaded with the DPLL, allowing the APLL1 domain to be locked to the DPLL reference input for synchronous clock generation. APLL2 can be used to generate unrelated clock frequencies either locked to the APLL1 domain or the free-running XO input.

The DPLL reference input mux supports automatic input selection or manual input selection through software or pin control. The device provides hitless switching with proprietary phase cancellation for superior phase transient performance (±50 ps typical). The reference clock input monitoring block monitors the clock inputs and will perform a hitless switchover or holdover when a loss of reference (LOR) is detected. A LOR condition can be detected upon any violation of the threshold limits set for the input monitors, which include amplitude, missing pulse, runt pulse, and 1-PPS (pulse-per-second) detectors. The threshold limits for each input detector can be set and enabled per clock input. The tuning word history monitor feature allows the initial output frequency accuracy upon entry into holdover to be determined by the historical average frequency when locked, minimizing the frequency and phase disturbance during a LOR condition.

The device has eight outputs with programmable drivers, allowing up to eight differential clocks, or a combination of differential clocks and up to four 1.8-V LVCMOS pairs (two outputs per pair). The output clocks can be selected from either APLL/VCO domain through the output muxes. The output dividers have a SYNC feature to allow multiple outputs to be phase-aligned. A 1-PPS output can be supported on Output 7 (OUT7). If needed, the user can enable the zero-delay mode (ZDM) synchronization to achieve deterministic phase alignment between an APLL1 clock on OUT7 and the selected reference input.

To support IEEE 1588 PTP slave clock or other clock steering applications, the DPLL also supports DCO mode with less than 0.001-ppb (part per billion) frequency resolution for precise frequency and phase adjustment through external software or pin control.

The device is fully programmable through I2C or SPI and supports custom start-up frequency configuration with the internal EEPROM, which is factory pre-programmed and in-system programmable if needed. Internal LDO regulators provide excellent PSNR to reduce the cost and complexity of the power delivery network. The clock input and PLL monitoring status can be observed through the status pins and interrupt registers for full diagnostic capability.