SNAS750B November   2020  – March 2021 LMK5C33216

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Timing Diagrams
  8. 8 Parameter Measurement Information
    1. 8.1 Differential Voltage Measurement Terminology
    2. 8.2 Output Clock Test Configurations
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
      1. 9.2.1 PLL Architecture Overview
      2. 9.2.2 DPLL
        1. 9.2.2.1 Independent DPLL Operation
        2. 9.2.2.2 Cascaded DPLL Operation
        3. 9.2.2.3 APLL Cascaded with DPLL
      3. 9.2.3 APLL-Only Mode
    3. 9.3 Feature Description
      1. 9.3.1  Oscillator Input (XO)
      2. 9.3.2  Reference Inputs
      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 Phase Cancellation
        2. 9.3.5.2 Hitless Switching With Phase Slew Control
        3. 9.3.5.3 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 Frequency Monitoring
          3. 9.3.7.2.3 Missing Pulse Monitor (Late Detect)
          4. 9.3.7.2.4 Runt Pulse Monitor (Early Detect)
          5. 9.3.7.2.5 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
          1. 9.3.8.1.1 APLL Phase Detector Frequency
          2. 9.3.8.1.2 APLL VCO Frequency
          3. 9.3.8.1.3 DPLL TDC Frequency
          4. 9.3.8.1.4 DPLL VCO Frequency
          5. 9.3.8.1.5 Clock Output Frequency
        2. 9.3.8.2  Analog PLLs (APLL1, APLL2, APLL3)
        3. 9.3.8.3  APLL Reference Paths
          1. 9.3.8.3.1 APLL XO Doubler
          2. 9.3.8.3.2 APLL XO Reference (R) Divider
        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 APLL N Divider with SDM
        6. 9.3.8.6  APLL Loop Filters (LF1, LF2, LF3)
        7. 9.3.8.7  APLL Voltage Controlled Oscillators (VCO1, VCO2, VCO3)
          1. 9.3.8.7.1 VCO Calibration
        8. 9.3.8.8  APLL VCO Clock Distribution Paths
        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 SYSREF
      13. 9.3.13 Output Delay
      14. 9.3.14 Clock Outputs (OUTx_P/N)
        1. 9.3.14.1 Differential Output
        2. 9.3.14.2 LVCMOS Output
        3. 9.3.14.3 Output Auto-Mute During LOL
      15. 9.3.15 Glitchless Output Clock Start-Up
      16. 9.3.16 Clock Output Interfacing and Termination
      17. 9.3.17 Output Synchronization (SYNC)
      18. 9.3.18 Zero-Delay Mode (ZDM) Synchronization
      19. 9.3.19 Time of Day (ToD) Counter
        1. 9.3.19.1 Configuring ToD Functionality
        2. 9.3.19.2 SPI as a Trigger Source
        3. 9.3.19.3 GPIO Pin as a ToD Trigger Source
          1. 9.3.19.3.1 An Example: Making a time measurement using ToD and GPIO1 as trigger
        4. 9.3.19.4 ToD Timing
        5. 9.3.19.5 Other ToD Behavior
    4. 9.4 Device Functional Modes
      1. 9.4.1 Device Start-Up
        1. 9.4.1.1 ROM Selection
        2. 9.4.1.2 EEPROM Overlay
      2. 9.4.2 DPLL Operating States
        1. 9.4.2.1 Free-Run
        2. 9.4.2.2 Lock Acquisition
        3. 9.4.2.3 DPLL Locked
        4. 9.4.2.4 Holdover
      3. 9.4.3 PLL Start-Up Sequence
      4. 9.4.4 Digitally-Controlled Oscillator (DCO) Frequency and Phase Adjustment
        1. 9.4.4.1 DPLL DCO Control
          1. 9.4.4.1.1 DPLL DCO Relative Adjustment Frequency Step Size
          2. 9.4.4.1.2 APLL DCO Frequency Step Size
      5. 9.4.5 APLL Frequency Control
      6. 9.4.6 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 Generation
      5. 9.5.5 General Register Programming Sequence
  10. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 Device Start-Up Sequence
      2. 10.1.2 Power Down (PD#) Pin
      3. 10.1.3 Strap Pins for Start-Up
      4. 10.1.4 ROM and EEPROM
      5. 10.1.5 Power Rail Sequencing, Power Supply Ramp Rate, and Mixing Supply Domains
        1. 10.1.5.1 Power-On Reset (POR) Circuit
        2. 10.1.5.2 Powering Up From a Single-Supply Rail
        3. 10.1.5.3 Power Up From Split-Supply Rails
        4. 10.1.5.4 Non-Monotonic or Slow Power-Up Supply Ramp
      6. 10.1.6 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. 10.3 Do's and Don'ts
  11. 11Power Supply Recommendations
    1. 11.1 Power Supply Bypassing
  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 Documentation Support
      1. 13.1.1 Related Documentation
    2. 13.2 Receiving Notification of Documentation Updates
    3. 13.3 Support Resources
    4. 13.4 Trademarks
    5. 13.5 Glossary
    6. 13.6 Electrostatic Discharge Caution
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

9.2.3 APLL-Only Mode

In APLL-only mode, the external XO input source determines the free-run frequency stability and accuracy of the output clocks. The DPLL blocks are not used and do not affect the APLLs. APLLs still can operate in cascaded mode or non-cascaded mode and also have DCO option through control register writes.

The principle of operation for APLL-only mode after power-on reset and initialization is as follows. If APLL1 or APLL2 is in cascaded mode as shown in Figure 9-6 (DPLL3 also is not used), VCO1 or VCO2 will track the VCO3 domain. APLLs lock in APLL priority order using bits: APLLx_STRT_PRTY. Cascading APLL1 or APLL2 from VCO3 provides a high-frequency, ultra-low-jitter reference clock to minimize the APLL2 or APLL3 in-band phase noise/jitter degradation could otherwise occur from a lower performance XO/TCXO/OCXO.

If APLL1 or APLL2 is not cascaded as shown in Figure 9-7, VCO1 or VCO2 will lock to the XO input in APLLx_STRT_PRTY order after initialization and operate independent of the APLL3 domain.

When operating in APLL-Only mode, it is recommended for frequency accuracy to use a 24-bit numerator and a programmable 24-bit denominator (PLLx_MODE = 0) instead of a fixed 40-bit denominator (PLLx_MODE = 1).

GUID-20200805-CA0I-78ZN-T492-LTJ78TJ3BCCV-low.svg Figure 9-7 APLL-Only Independent Mode