SNAS866 December   2023 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 Application and Implementation
    1. 7.1 Applications Information
      1. 7.1.1 SYNC Input Configuration
      2. 7.1.2 Treatment of Unused Pins
      3. 7.1.3 Current Consumption
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
      3. 7.2.3 Application Plots
    3. 7.3 Power Supply Recommendations
    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

5.7 Timing Diagram

GUID-20210305-CA0I-XSG7-BVBT-N7JTRXCFJRJM-low.svg Figure 5-1 Serial Data Input Timing Diagram

There are several other considerations for writing on the SPI:

  • The R/W bit must be set to 0.
  • The data on SDI pin is clocked into a shift register on each rising edge on the SCK pin.
  • The CS# must be held low for data to be clocked. Device will ignore clock pulses if CS# is held high.
  • Recommended SPI settings for this device are CPOL=0 and CPHA=0.
  • When SCK and SDI lines are shared between devices, TI recommends to hold the CS# line high on the device that is not to be clocked.

There are several other considerations for SPI readback:

  • The R/W bit must be set to 1.
  • The MUXOUT pin will always be low for the address portion of the transaction.
  • The data on MUXOUT is clocked out at the falling edge of SCK. In other words, the readback data will be available at the MUXOUT pin tCD after the clock falling edge.
  • The data portion of the transition on the SDI line is always ignored.
  • The MUXOUT pin does not automatically tri-state after a readback transaction completes. When sharing the SPI bus readback pin with other devices, set MUXOUT_EN=0 after all readback transactions from device are complete to manually tri-state the MUXOUT pin, permitting other devices to control the readback line.
  • The values read back, even for R/W bits are not always the value written but rather an internal device state that takes into account the programmed value as well as other factors, such as pin states.