SNAS848 December   2023 LMK5C33216A

PRODUCTION DATA  

  1.   1
  2. Features
  3. Applications
  4. Description
  5. Pin Configuration and Functions
  6. Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Timing Diagrams
    7. 5.7 Typical Characteristics
  7. Parameter Measurement Information
    1. 6.1 Differential Voltage Measurement Terminology
    2. 6.2 Output Clock Test Configurations
  8. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
      1. 7.2.1 PLL Architecture Overview
      2. 7.2.2 DPLL
        1. 7.2.2.1 Independent DPLL Operation
        2. 7.2.2.2 Cascaded DPLL Operation
        3. 7.2.2.3 APLL Cascaded with DPLL
      3. 7.2.3 APLL-Only Mode
    3. 7.3 Feature Description
      1. 7.3.1  Oscillator Input (XO)
      2. 7.3.2  Reference Inputs
      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 Phase Cancellation
        2. 7.3.5.2 Hitless Switching With Phase Slew Control
        3. 7.3.5.3 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 Frequency Monitoring
          3. 7.3.7.2.3 Missing Pulse Monitor (Late Detect)
          4. 7.3.7.2.4 Runt Pulse Monitor (Early Detect)
          5. 7.3.7.2.5 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
          1. 7.3.8.1.1 APLL Phase Detector Frequency
          2. 7.3.8.1.2 APLL VCO Frequency
          3. 7.3.8.1.3 DPLL TDC Frequency
          4. 7.3.8.1.4 DPLL VCO Frequency
          5. 7.3.8.1.5 Clock Output Frequency
        2. 7.3.8.2  Analog PLLs (APLL1, APLL2, APLL3)
        3. 7.3.8.3  APLL Reference Paths
          1. 7.3.8.3.1 APLL XO Doubler
          2. 7.3.8.3.2 APLL XO Reference (R) Divider
        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 APLL N Divider With SDM
        6. 7.3.8.6  APLL Loop Filters (LF1, LF2, LF3)
        7. 7.3.8.7  APLL Voltage-Controlled Oscillators (VCO1, VCO2, VCO3)
          1. 7.3.8.7.1 VCO Calibration
        8. 7.3.8.8  APLL VCO Clock Distribution Paths
        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 SYSREF/1-PPS
      13. 7.3.13 Output Delay
      14. 7.3.14 Clock Outputs (OUTx_P/N)
        1. 7.3.14.1 Differential Output
        2. 7.3.14.2 LVCMOS Output
        3. 7.3.14.3 SYSREF/1-PPS Output Replication
        4. 7.3.14.4 Output Auto-Mute During LOL
      15. 7.3.15 Glitchless Output Clock Start-Up
      16. 7.3.16 Clock Output Interfacing and Termination
      17. 7.3.17 Output Synchronization (SYNC)
      18. 7.3.18 Zero-Delay Mode (ZDM)
      19. 7.3.19 Time Elapsed Counter (TEC)
        1. 7.3.19.1 Configuring TEC Functionality
        2. 7.3.19.2 SPI as a Trigger Source
        3. 7.3.19.3 GPIO Pin as a TEC Trigger Source
          1. 7.3.19.3.1 An Example: Making a Time Elapsed Measurement Using TEC and GPIO1 as Trigger
        4. 7.3.19.4 TEC Timing
        5. 7.3.19.5 Other TEC Behavior
    4. 7.4 Device Functional Modes
      1. 7.4.1 Device Start-Up
        1. 7.4.1.1 ROM Selection
        2. 7.4.1.2 EEPROM Overlay
      2. 7.4.2 DPLL Operating States
        1. 7.4.2.1 Free-Run
        2. 7.4.2.2 Lock Acquisition
        3. 7.4.2.3 DPLL Locked
        4. 7.4.2.4 Holdover
      3. 7.4.3 PLL Start-Up Sequence
      4. 7.4.4 Digitally-Controlled Oscillator (DCO) Frequency and Phase Adjustment
        1. 7.4.4.1 DPLL DCO Control
          1. 7.4.4.1.1 DPLL DCO Relative Adjustment Frequency Step Size
          2. 7.4.4.1.2 APLL DCO Frequency Step Size
      5. 7.4.5 APLL Frequency Control
      6. 7.4.6 DPLL Programmable Phase Delay
    5. 7.5 Programming
      1. 7.5.1 Interface and Control
      2. 7.5.2 I2C Serial Interface
        1. 7.5.2.1 I2C Block Register Transfers
      3. 7.5.3 SPI Serial Interface
        1. 7.5.3.1 SPI Block Register Transfer
      4. 7.5.4 Register Map Generation
      5. 7.5.5 General Register Programming Sequence
  9. Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Device Start-Up Sequence
      2. 8.1.2 Power Down (PD#) Pin
      3. 8.1.3 Strap Pins for Start-Up
      4. 8.1.4 Pin States
      5. 8.1.5 ROM and EEPROM
      6. 8.1.6 Power Rail Sequencing, Power Supply Ramp Rate, and Mixing Supply Domains
        1. 8.1.6.1 Power-On Reset (POR) Circuit
        2. 8.1.6.2 Powering Up From a Single-Supply Rail
        3. 8.1.6.3 Power Up From Split-Supply Rails
        4. 8.1.6.4 Non-Monotonic or Slow Power-Up Supply Ramp
      7. 8.1.7 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
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
      2. 8.5.2 Layout Example
      3. 8.5.3 Thermal Reliability
  10. Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Development Support
        1. 9.1.1.1 Clock Tree Architect Programming Software
        2. 9.1.1.2 Texas Instruments Clocks and Synthesizers (TICS) Pro Software
        3. 9.1.1.3 PLLatinumâ„¢ Simulation Tool
    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 Glossary
    7. 9.7 Electrostatic Discharge Caution
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

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

Independent DPLL Operation

In the independent mode, each DPLL can select a reference as preferred. DPLL's can share the same reference, or each select a different reference. At start-up, each APLL will lock to the XO input after initialization and operate in free-run mode. When a valid DPLL reference input is detected, each DPLL begins lock acquisition on independent reference priority. Each DPLL's TDC compares the phase of the selected reference input clock to the FB divider clock from the respective VCO and generates a digital correction word corresponding to the phase error. The correction word is filtered by the digital loop filter (DLF), and the DLF output adjusts the APLL N divider numerator to pull the VCO frequency into lock with the reference input.

Since each DPLL can work independently in this mode, the DPLLs can lock or unlock without impacting other channels.

When selecting an XO frequency, TI recommends to avoid ratios falling near integer or half integer boundaries to minimize spurious noise. Ideally, it is best to select a XO frequency that results in an APLL fractional N divider ratio (NUM/DEN) between the range of 0.125 to 0.45 and 0.55 to 0.875. Choosing a higher frequency XO is better for jitter performance, especially for APLL1 and APLL2 outputs. If the XO frequency or phase noise performance has gap to what performance is required for APLL1 or APLL2 outputs, there is an option to adopt cascaded mode using APLL3 as the reference to APLL1 or APLL2.

GUID-111FC695-FC66-4AB0-8FDF-911FE51211CA-low.svgFigure 7-3 DPLL Independent Mode