SLVSLJ4 April   2026 TCA9847

ADVANCE INFORMATION  

  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 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
    4. 7.4 Device Functional Modes
      1. 7.4.1 RESET Input
      2. 7.4.2 Power-On Reset
    5. 7.5 Programming
      1. 7.5.1 I2C Interface
      2. 7.5.2 Device Address
      3. 7.5.3 Bus Transactions
        1. 7.5.3.1 Writes
        2. 7.5.3.2 Reads
      4. 7.5.4 Control Register
      5. 7.5.5 RESET Input
      6. 7.5.6 Power-On Reset
      7. 7.5.7 Software Reset
      8. 7.5.8 Device ID
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
        1. 8.2.1.1 Voltage Translation Requirements
      2. 8.2.2 Detailed Design Procedure
    3. 8.3 Power Supply Recommendations
      1. 8.3.1 Power-On Reset Requirements
    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 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information
    1. 11.1 Tape and Reel Information
    2. 11.2 Mechanical Data

封装选项

机械数据 (封装 | 引脚)
散热焊盘机械数据 (封装 | 引脚)

7.1 Overview

The TCA9847 is an 8-channel, bidirectional translating I2C multiplexer. The controller SCL/SDA signal pair is directed to eight channels of target devices, SC0/SD0-SC7/SD7. Any individual downstream channel can be selected as well as any combination of the eight channels.

The device offers an active-low RESET input which resets the state machine and allows the TCA9847 to recover if one of the downstream I2C buses get stuck in a low state. The state machine of the device can also be reset by cycling the power supply, VCC, also known as a power-on reset (POR). Both the RESET function and a POR cause all channels to be deselected.

The connections of the I2C data path are controlled by the same I2C controller device that is switched to communicate with multiple I2C targets. After the successful acknowledgment of the target address (hardware selectable by A0 and A1 pins), a single 8-bit control register is written to or read from to determine the selected channels.

The TCA9847 can also be used for voltage translation, allowing the use of different bus voltages on each SCn/SDn pair such that 0.65V, 0.8V, 1.2V, or 1.8V parts can communicate with 3.3V parts. This action is achieved by using external pullup resistors to pull the bus up to the desired voltage for the controller and each target channel.