SNAS835A September   2022  – February 2025 LMK5B33414

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison
  6. 5 Pin Configuration and Functions
  7. 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
  8. 7 Parameter Measurement Information
    1. 7.1 Differential Voltage Measurement Terminology
    2. 7.2 Output Clock Test Configurations
  9. 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 1PPS 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 1PPS 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 Frequency Detector (PFD) and Charge Pump
          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 Feedback Divider Paths
          1. 8.3.8.4.1 APLL N Divider With Sigma-Delta Modulator (SDM)
        5. 8.3.8.5  APLL Loop Filters (LF1, LF2, LF3)
        6. 8.3.8.6  APLL Voltage-Controlled Oscillators (VCO1, VCO2, VCO3)
          1. 8.3.8.6.1 VCO Calibration
        7. 8.3.8.7  APLL VCO Clock Distribution Paths
        8. 8.3.8.8  DPLL Reference (R) Divider Paths
        9. 8.3.8.9  DPLL Time-to-Digital Converter (TDC)
        10. 8.3.8.10 DPLL Loop Filter (DLF)
        11. 8.3.8.11 DPLL Feedback (FB) Divider Path
      9. 8.3.9  Output Clock Distribution
      10. 8.3.10 Output Source Muxes
      11. 8.3.11 Output Channel Muxes
      12. 8.3.12 Output Dividers (OD)
      13. 8.3.13 SYSREF/1PPS Output
      14. 8.3.14 Output Delay
      15. 8.3.15 Clock Output Drivers
        1. 8.3.15.1 Differential Output
        2. 8.3.15.2 LVCMOS Output
      16. 8.3.16 Clock Output Interfacing and Termination
      17. 8.3.17 Glitchless Output Clock Start-Up
      18. 8.3.18 Output Auto-Mute During LOL
      19. 8.3.19 Output Synchronization (SYNC)
      20. 8.3.20 Zero-Delay Mode (ZDM)
      21. 8.3.21 DPLL Programmable Phase Delay
      22. 8.3.22 Time Elapsed Counter (TEC)
        1. 8.3.22.1 Configuring TEC Functionality
        2. 8.3.22.2 SPI as a Trigger Source
        3. 8.3.22.3 GPIO Pin as a TEC Trigger Source
          1. 8.3.22.3.1 An Example: Making a Time Elapsed Measurement Using TEC and GPIO1 as Trigger
        4. 8.3.22.4 TEC Timing
        5. 8.3.22.5 Other TEC Behavior
    4. 8.4 Device Functional Modes
      1. 8.4.1 DPLL Operating States
        1. 8.4.1.1 Free-Run
        2. 8.4.1.2 Lock Acquisition
        3. 8.4.1.3 DPLL Locked
        4. 8.4.1.4 Holdover
      2. 8.4.2 Digitally-Controlled Oscillator (DCO) Frequency and Phase Adjustment
        1. 8.4.2.1 DPLL DCO Control
        2. 8.4.2.2 DPLL DCO Relative Adjustment Frequency Step Size
        3. 8.4.2.3 APLL DCO Frequency Step Size
      3. 8.4.3 APLL Frequency Control
      4. 8.4.4 Device Start-Up
        1. 8.4.4.1 Device Power-On Reset (POR)
        2. 8.4.4.2 PLL Start-Up Sequence
        3. 8.4.4.3 Start-Up Options for Register Configuration
        4. 8.4.4.4 GPIO1 and SCS_ADD Functionalities
        5. 8.4.4.5 ROM Page Selection
        6. 8.4.4.6 ROM Detailed Description
        7. 8.4.4.7 EEPROM Overlay
    5. 8.5 Programming
      1. 8.5.1 Memory Overview
      2. 8.5.2 Interface and Control
        1. 8.5.2.1 Programming Through TICS Pro
        2. 8.5.2.2 SPI Serial Interface
        3. 8.5.2.3 I2C Serial Interface
      3. 8.5.3 General Register Programming Sequence
      4. 8.5.4 Steps to Program the EEPROM
        1. 8.5.4.1 Overview of the SRAM Programming Methods
        2. 8.5.4.2 EEPROM Programming With the Register Commit Method
        3. 8.5.4.3 EEPROM Programming With the Direct Writes Method or Mixed Method
        4. 8.5.4.4 Five MSBs of the I2C Address and the EEPROM Revision Number
  10. 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 Power 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 Best Design Practices
    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
  11. 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 Electrostatic Discharge Caution
    7. 10.7 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

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

8.3.22 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 can 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 selected using the GPIO polarity invert register. After each TEC event, the counter values is captured and the application can 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 7.5ns with a total measurement time over 59 minutes depending on exact configuration. Reading 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 needs to detect roll-over of counter register which complicates Equation 12 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 12 to calculate the elapsed time. The worst-case error is twice the TEC counter clock period. Table 8-10 lists some common TEC clock frequencies/periods and roll-over times.

Equation 12. Elapsed Time = (2nd captured TEC value – 1st captured TEC value) / TEC Clock Rate

The TEC_CNTR register is split across five registers.

Table 8-10 Common TEC Clock Frequencies and Roll-Over Times
PLL SOURCE VCO FREQUENCY TEC CLOCK FREQUENCY TEC CLOCK PERIOD (t) ROLL-OVER TIME
PLL3 2500MHz 312.5MHz Approximately 3.17ns Approximately 58.6 minutes
PLL2 5950MHz 297.5MHz Approximately 3.361ns Approximately 61.6 minutes
PLL2 5898.24MHz 294.912MHz Approximately 3.391ns Approximately 62.1 minutes
PLL2 5625MHz 281.25MHz Approximately 3.556ns Approximately 65.1 minutes
PLL2 5600MHz 280MHz Approximately 3.571ns Approximately 65.4 minutes
LMK5B33414 TEC Clock and Counter Figure 8-33 TEC Clock and Counter

Figure 8-34 illustrates the states of the Time Elapsed Counter function.


LMK5B33414 State Diagram of TEC
Figure 8-34 State Diagram of TEC