SNAS866A December   2023  – September 2024 LMX1214

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
    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. 6.3.4 AUXCLK Output
        1. 6.3.4.1 AUXCLKOUT Output Format
        2. 6.3.4.2 AUXCLK_DIV_PRE and AUXCLK_DIV Dividers
      5. 6.3.5 SYNC Input Pins
        1. 6.3.5.1 SYNC Pins Common-Mode Voltage
        2. 6.3.5.2 Windowing Feature
    4. 6.4 Device Functional Modes Configurations
      1. 6.4.1 Pin Mode Control
  8. 7 Register Map
    1. 7.1 Device Registers
  9. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 SYNC Input Configuration
      2. 8.1.2 Treatment of Unused Pins
      3. 8.1.3 Current Consumption
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Plots
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
    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 Electrostatic Discharge Caution
    7. 9.7 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information
    1. 11.1 Tape and Reel Information

Package Options

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

6.3.1 Power-On Reset

When the device is powered up, the power-on reset (POR) resets all registers to a default state as well as resets all state machines and dividers. For the power-on reset state, all the dividers are bypassed and the device performs as a 4-output buffer. Wait 100 µs after the power supply rails before programming other registers to verify that this reset is finished. When there is no input clock present, the device power-on reset happens properly and functions well, but the device draws less current. The current changes after an input clock is added.

Performing a software power-on reset by writing RESET = 1 in the SPI bus is also possible and generally good practice. The RESET bit self-clears when the user writes to another register. The SPI bus can be used to override these states to the desired settings.

Although the device does have an automatic power-on reset, the device can be impacted by different ramp rates on the different supply pins, especially in the presence of a strong input clock signal. TI therefore recommends to do a software reset after POR. This can be done by programming RESET = 1. The reset bit can be cleared by programming any other register or setting RESET back to 0. Even at the maximum allowed SPI bus speed, the software reset event always completes before the subsequent SPI write.