SLVSLJ6A May   2026  – September 2026 TCA9849

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 (Global)
    6. 5.6 I2C Interface Timing Requirements
    7. 5.7 Reset Timing Requirements
    8. 5.8 Switching Characteristics
  7. 6 Typical Characteristics
  8. 7 Parameter Measurement Information
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
    4. 8.4 Device Functional Modes
      1. 8.4.1 RESET Input
      2. 8.4.2 Power-On Reset
    5. 8.5 Programming
      1. 8.5.1 I2C Interface
      2. 8.5.2 Device Address
      3. 8.5.3 Bus Transactions
        1. 8.5.3.1 Writes
        2. 8.5.3.2 Reads
      4. 8.5.4 Control Register
      5. 8.5.5 RESET Input
      6. 8.5.6 Power-On Reset
        1. 8.5.6.1 Software Reset
        2. 8.5.6.2 Device ID
  10. 9 Application and Implementation
    1. 9.1 Application Information
    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 Power Supply Recommendations
      1. 9.3.1 Power-On Reset Requirements
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

8.5.6.2 Device ID

The Device ID is a 24-bit (3-byte) read-only value containing the following fields:

  • 12 bits: manufacturer identifier (unique per manufacturer, for example, TI)
  • 9 bits: part number (assigned by the manufacturer)
  • 3 bits: die revision (assigned by the manufacturer)

The Device ID is hardwired and accessible using the following procedure:

  1. Send a START command.
  2. The controller transmits the Reserved Device ID I²C address (1111 1000) with R/W = 0 (write).
  3. The controller sends the target device address, with the LSB as “don’t care.” Only the matching device acknowledges.
  4. Issue a Repeated START condition.
    1. A STOP command followed by a START command resets the target state machine and the Device ID read cannot be performed. Also, a STOP command or a Re-START command followed by an access to another target device resets the target state machine and the Device ID Read cannot be performed.
  5. The controller sends the Reserved Device ID I²C address (1111 1001) with R/W = 1 (read).
  6. The device transmits the Device ID in the following order:
    1. First byte + 4MSBs of second byte: Manufacturer ID (12 bits)
    2. 4LSBs of second byte + 5MSBs of third byte: Part Identification (9 bits)
    3. 3LSBs of third byte: Die Revision (3 bits)
  7. The controller completes the read by sending a NACK after the last byte, resetting the device internal state machine and then issuing a STOP command.

If the controller sends additional acknowledgments after the third byte, the device restarts the data sequence from the first byte.

TCA9849 Device IDFigure 8-7 Device ID
TCA9849 Device ID SequenceFigure 8-8 Device ID Sequence