SNAS851 December   2023 LMX1906-SP

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 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 Requirements
    7. 5.7 Timing Diagram
    8. 5.8 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
      1. 6.1.1 Range of Dividers and Multiplier
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Power On Reset
      2. 6.3.2 Temperature Sensor
      3. 6.3.3 Clock Outputs
        1. 6.3.3.1 Clock Output Buffers
        2. 6.3.3.2 Clock MUX
        3. 6.3.3.3 Clock Divider
        4. 6.3.3.4 Clock Multiplier
          1. 6.3.3.4.1 General Information about the Clock Multiplier
          2. 6.3.3.4.2 State Machine Clock for the Clock Multiplier
            1. 6.3.3.4.2.1 State Machine Clock
          3. 6.3.3.4.3 Calibration for the Clock Multiplier
          4. 6.3.3.4.4 Lock Detect for the Clock Multiplier
          5. 6.3.3.4.5 Watchdog Timer
      4. 6.3.4 Device Functional Modes Configurations
      5. 6.3.5 LOGICLK Output
        1. 6.3.5.1 LOGICLK Output Format
        2. 6.3.5.2 LOGICLK_DIV_PRE and LOGICLK_DIV Dividers
      6. 6.3.6 SYSREF
        1. 6.3.6.1 SYSREF Output Buffers
          1. 6.3.6.1.1 SYSREF Output Buffers for Main Clocks (SYSREFOUT)
          2. 6.3.6.1.2 SYSREF Output Buffer for LOGICLK
        2. 6.3.6.2 SYSREF Frequency and Delay Generation
        3. 6.3.6.3 SYSREFREQ pins and SYSREFREQ_FORCE Field
          1. 6.3.6.3.1 SYSREFREQ Pins Common-Mode Voltage
          2. 6.3.6.3.2 SYSREFREQ Windowing Feature
            1. 6.3.6.3.2.1 General Procedure Flowchart for SYSREF Windowing Operation
            2. 6.3.6.3.2.2 SYSREFREQ Repeater Mode With Delay Gen (Retime)
            3. 6.3.6.3.2.3 Other Pointers With SYSREF Windowing
            4. 6.3.6.3.2.4 For Glitch-Free Output
            5. 6.3.6.3.2.5 If Using SYNC Feature
          3. 6.3.6.3.3 SYNC Feature
      7. 6.3.7 Pin Mode Control
        1. 6.3.7.1 Chip Enable (CE)
        2. 6.3.7.2 Output Channel Control
        3. 6.3.7.3 Logic Output Control
        4. 6.3.7.4 SYSREF Output Control
        5. 6.3.7.5 Device Mode Selection
        6. 6.3.7.6 Divider or Multiplier Value Selection
        7. 6.3.7.7 Calibration Control Pin
        8. 6.3.7.8 Output Power Control
  8. 7 Application and Implementation
    1. 7.1 Applications Information
      1. 7.1.1 SYSREFREQ Input Configuration
      2. 7.1.2 Treatment of Unused Pins
      3. 7.1.3 Current Consumption
    2. 7.2 Typical Applications
      1. 7.2.1 Local Oscillator Distribution Application
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
        3. 7.2.1.3 Application Plots
      2. 7.2.2 JESD204B/C Clock Distribution Application
    3. 7.3 Power Supply Recommendations
      1. 7.3.1 Power-Up Timing
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
    5. 7.5 Register Map
      1. 7.5.1 Device Registers
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
    2. 8.2 Receiving Notification of Documentation Updates
    3. 8.3 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

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

6.3.2 Temperature Sensor

The junction temperature can be read back for purposes such as characterization or to make adjustments based on temperature. Such adjustments might include adjusting CLKOUTx_PWR to make the output power more stable or using external or digital delays to compensate for changes in propagation delay over temperature.

The junction temperature is typically higher than the ambient temperature due to power dissipation from the outputs and other functions on the device. Equation 1 shows the relationship between the code read back and the junction temperature.

Equation 1. Temperature = 0.65 × Code – 351

Equation 1 is based on a best-fit line created from three devices from slow, nominal, and fast corner lots (nine parts total). The worst-case variation of the actual temperature from the temperature predicted by the best-fit line was 13°C, which works out to 20 codes.