SNAS816B March   2022  – July 2022 LMK5B33216

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Timing Diagrams
    7. 6.7 Typical Characteristics
  7. 7 Parameter Measurement Information
    1. 7.1 Differential Voltage Measurement Terminology
    2. 7.2 Output Clock Test Configurations
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
      1. 8.2.1 PLL Architecture Overview
      2. 8.2.2 DPLL
        1. 8.2.2.1 Independent DPLL Operation
        2. 8.2.2.2 Cascaded DPLL Operation
        3. 8.2.2.3 APLL Cascaded With DPLL
      3. 8.2.3 APLL-Only Mode
    3. 8.3 Feature Description
      1. 8.3.1  Oscillator Input (XO)
      2. 8.3.2  Reference Inputs
      3. 8.3.3  Clock Input Interfacing and Termination
      4. 8.3.4  Reference Input Mux Selection
        1. 8.3.4.1 Automatic Input Selection
        2. 8.3.4.2 Manual Input Selection
      5. 8.3.5  Hitless Switching
        1. 8.3.5.1 Hitless Switching With Phase Cancellation
        2. 8.3.5.2 Hitless Switching With Phase Slew Control
        3. 8.3.5.3 Hitless Switching With 1-PPS Inputs
      6. 8.3.6  Gapped Clock Support on Reference Inputs
      7. 8.3.7  Input Clock and PLL Monitoring, Status, and Interrupts
        1. 8.3.7.1 XO Input Monitoring
        2. 8.3.7.2 Reference Input Monitoring
          1. 8.3.7.2.1 Reference Validation Timer
          2. 8.3.7.2.2 Frequency Monitoring
          3. 8.3.7.2.3 Missing Pulse Monitor (Late Detect)
          4. 8.3.7.2.4 Runt Pulse Monitor (Early Detect)
          5. 8.3.7.2.5 Phase Valid Monitor for 1-PPS Inputs
        3. 8.3.7.3 PLL Lock Detectors
        4. 8.3.7.4 Tuning Word History
        5. 8.3.7.5 Status Outputs
        6. 8.3.7.6 Interrupt
      8. 8.3.8  PLL Relationships
        1. 8.3.8.1  PLL Frequency Relationships
          1. 8.3.8.1.1 APLL Phase Detector Frequency
          2. 8.3.8.1.2 APLL VCO Frequency
          3. 8.3.8.1.3 DPLL TDC Frequency
          4. 8.3.8.1.4 DPLL VCO Frequency
          5. 8.3.8.1.5 Clock Output Frequency
        2. 8.3.8.2  Analog PLLs (APLL1, APLL2, APLL3)
        3. 8.3.8.3  APLL Reference Paths
          1. 8.3.8.3.1 APLL XO Doubler
          2. 8.3.8.3.2 APLL XO Reference (R) Divider
        4. 8.3.8.4  APLL Phase Frequency Detector (PFD) and Charge Pump
        5. 8.3.8.5  APLL Feedback Divider Paths
          1. 8.3.8.5.1 APLL N Divider With SDM
        6. 8.3.8.6  APLL Loop Filters (LF1, LF2, LF3)
        7. 8.3.8.7  APLL Voltage-Controlled Oscillators (VCO1, VCO2, VCO3)
          1. 8.3.8.7.1 VCO Calibration
        8. 8.3.8.8  APLL VCO Clock Distribution Paths
        9. 8.3.8.9  DPLL Reference (R) Divider Paths
        10. 8.3.8.10 DPLL Time-to-Digital Converter (TDC)
        11. 8.3.8.11 DPLL Loop Filter (DLF)
        12. 8.3.8.12 DPLL Feedback (FB) Divider Path
      9. 8.3.9  Output Clock Distribution
      10. 8.3.10 Output Channel Muxes
      11. 8.3.11 Output Dividers (OD)
      12. 8.3.12 SYSREF/1PPS
      13. 8.3.13 Output Delay
      14. 8.3.14 Clock Outputs (OUTx_P/N)
        1. 8.3.14.1 Differential Output
        2. 8.3.14.2 LVCMOS Output
        3. 8.3.14.3 SYSREF/1PPS Output Replication
        4. 8.3.14.4 Output Auto-Mute During LOL
      15. 8.3.15 Glitchless Output Clock Start-Up
      16. 8.3.16 Clock Output Interfacing and Termination
      17. 8.3.17 Output Synchronization (SYNC)
      18. 8.3.18 Zero-Delay Mode (ZDM) Synchronization
      19. 8.3.19 Time Elapsed Counter (TEC)
        1. 8.3.19.1 Configuring TEC Functionality
        2. 8.3.19.2 SPI as a Trigger Source
        3. 8.3.19.3 GPIO Pin as a TEC Trigger Source
          1. 8.3.19.3.1 An Example: Making a Time Elapsed Measurement Using TEC and GPIO1 as Trigger
        4. 8.3.19.4 TEC Timing
        5. 8.3.19.5 Other TEC Behavior
    4. 8.4 Device Functional Modes
      1. 8.4.1 Device Start-Up
        1. 8.4.1.1 ROM Selection
        2. 8.4.1.2 EEPROM Overlay
      2. 8.4.2 DPLL Operating States
        1. 8.4.2.1 Free-Run
        2. 8.4.2.2 Lock Acquisition
        3. 8.4.2.3 DPLL Locked
        4. 8.4.2.4 Holdover
      3. 8.4.3 PLL Start-Up Sequence
      4. 8.4.4 Digitally-Controlled Oscillator (DCO) Frequency and Phase Adjustment
        1. 8.4.4.1 DPLL DCO Control
          1. 8.4.4.1.1 DPLL DCO Relative Adjustment Frequency Step Size
          2. 8.4.4.1.2 APLL DCO Frequency Step Size
      5. 8.4.5 APLL Frequency Control
      6. 8.4.6 Zero-Delay Mode Synchronization
    5. 8.5 Programming
      1. 8.5.1 Interface and Control
      2. 8.5.2 I2C Serial Interface
        1. 8.5.2.1 I2C Block Register Transfers
      3. 8.5.3 SPI Serial Interface
        1. 8.5.3.1 SPI Block Register Transfer
      4. 8.5.4 Register Map Generation
      5. 8.5.5 General Register Programming Sequence
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Device Start-Up Sequence
      2. 9.1.2 Power Down (PD#) Pin
      3. 9.1.3 Strap Pins for Start-Up
      4. 9.1.4 Pin States
      5. 9.1.5 ROM and EEPROM
      6. 9.1.6 Power Rail Sequencing, Power Supply Ramp Rate, and Mixing Supply Domains
        1. 9.1.6.1 Power-On Reset (POR) Circuit
        2. 9.1.6.2 Powering Up From a Single-Supply Rail
        3. 9.1.6.3 Power Up From Split-Supply Rails
        4. 9.1.6.4 Non-Monotonic or Slow Power-Up Supply Ramp
      7. 9.1.7 Slow or Delayed XO Start-Up
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
    3. 9.3 Do's and Don'ts
    4. 9.4 Power Supply Recommendations
      1. 9.4.1 Power Supply Bypassing
    5. 9.5 Layout
      1. 9.5.1 Layout Guidelines
      2. 9.5.2 Layout Example
      3. 9.5.3 Thermal Reliability
  10. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Development Support
        1. 10.1.1.1 Clock Tree Architect Programming Software
        2. 10.1.1.2 Texas Instruments Clocks and Synthesizers (TICS) Pro Software
        3. 10.1.1.3 PLLatinum™ Simulation Tool
    2. 10.2 Documentation Support
      1. 10.2.1 Related Documentation
    3. 10.3 Receiving Notification of Documentation Updates
    4. 10.4 Support Resources
    5. 10.5 Trademarks
    6. 10.6 Glossary
    7. 10.7 Electrostatic Discharge Caution
  11. 11Mechanical, Packaging, and Orderable Information

Package Options

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

8.3.19 Time Elapsed Counter (TEC)

The Time Elapsed Counter (TEC) allows the user to make a precise time measurement between two (or more) events. The events may be either a rising or falling edge of a GPIO pin or a falling edge of the SPI SCS pin. Any GPIO pin can be programmed for TEC input. Rising or falling polarity can be chosen using the GPIO polarity invert register. After each TEC event, the counter values is captured and the application may read back a 40-bit value. The elapsed time is calculated based on the difference in the read back values. The accuracy of the measurement is better than 7.5 ns with a total measurement time over 59 minutes depending on exact configuration. It is necessary to read back at least the LSB of the TEC_CNTR to re-arm the TEC counter capture.

The TEC counter is clocked at a frequency based on PLL3 VCO frequency ÷8 or PLL2 VCO frequency ÷ 20. A time measurement is made by below steps.

  1. Reset the TEC counter value. Recommended to reduce chance of counter roll-over between TEC capture events, but optional. If the reset is not done the user would need to detect roll-over of counter register which will complicate Equation 10 for elapsed time calculation.
  2. Trigger TEC capture event and read back the TEC registers containing the stored counter value.
  3. Trigger the TEC capture event a second time and read back the TEC registers containing the stored counter value.
  4. Use Equation 10 to calculate the elapsed time. The worst-case error is twice the TEC counter clock period. Table 8-4 lists some common TEC clock frequencies/periods and roll-over times.

Equation 10. Elapsed Time = (2nd captured TEC value - 1st captured TEC value) / TEC Clock Rate

The TEC_CNTR register is split across five registers.

Table 8-4 Common TEC Clock Frequencies and Roll-Over Times
PLL SOURCE VCO FREQUENCY TEC CLOCK FREQUENCY TEC CLOCK PERIOD (t) ROLL-OVER TIME
PLL3 2500 MHz 312.5 MHz ~3.17 ns ~58.6 minutes
PLL2 5950 MHz 297.5 MHz ~3.361 ns ~61.6 minutes
PLL2 5898.24 MHz 294.912 MHz ~3.391 ns ~62.1 minutes
PLL2 5625 MHz 281.25 MHz ~3.556 ns ~65.1 minutes
PLL2 5600 MHz 280 MHz ~3.571 ns ~65.4 minutes
Figure 8-30 TEC Clock and Counter

Figure 8-31 illustrates the states of the Time Elapsed Counter function.



Figure 8-31 State Diagram of TEC