SLVSLJ4A April   2026  – July 2026 TCA9847

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
    9. 5.9 Typical 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. 8.2.3 Application Curves
    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

8.2.2 Detailed Design Procedure

After all the targets are assigned to the appropriate target channels and bus voltages are identified, the pullup resistors, Rp, for each of the buses need to be selected appropriately. The minimum pullup resistance is a function of VDPUX, VOL,(max), and IOL as shown in Equation 1:

Equation 1. TCA9847

The maximum pullup resistance is a function of the maximum rise time, tr (300ns for fast-mode operation, fSCL = 400kHz) and bus capacitance, Cb as shown in Equation 2:

Equation 2. TCA9847

The maximum bus capacitance for an I2C bus must not exceed 400pF for fast-mode operation. The bus capacitance can be approximated by adding the capacitance of the TCA9847, Cio(OFF), the capacitance of wires, connections and traces, and the capacitance of each individual target on a given channel. If multiple channels are activated simultaneously, each of the targets on all channels contribute to total bus capacitance.