SCPS259F December   2014  – March 2026 TCA9617B

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 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
      1. 7.3.1 Bidirectional Level Translation
      2. 7.3.2 Low to High Transition Characteristics (B to A)
      3. 7.3.3 High-to-Low Transition Characteristics (A to B)
    4. 7.4 Device Functional Modes
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Standard Application
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Pullup Resistor Sizing
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Star Application
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
        3. 8.2.2.3 Application Curves
      3. 8.2.3 Series Application
        1. 8.2.3.1 Design Requirements
        2. 8.2.3.2 Detailed Design Procedure
        3. 8.2.3.3 Application Curves
    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 Receiving Notification of Documentation Updates
    2. 9.2 Support Resources
    3. 9.3 Trademarks
    4. 9.4 Electrostatic Discharge Caution
    5. 9.5 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information
8.2.1.2.1 Pullup Resistor Sizing

For the TCA9617B to function correctly, all devices on the B-side must be able to pull the B-side below VILB. This means that the VOL of any device on the B-side must not exceed 0.4V for proper operation.

The VOL of a device can be adjusted by changing the IOL through the device which is set by the pull-up resistor value. The pull-up resistor on the B-side must be carefully selected to make sure the logic levels are transferred correctly to the A-side. Please see additional information in this application note:I2C Bus Pull-up Resistor Calculation.

Figure 8-2:

  • Point 1: The logic low driven by an external target or controller device connected to the B-side.
  • Point 2: The pedestal created by an external target or controller device releasing the B-side. The voltage rises to a VOLB and waits until the A-side voltage rises to 30% of VCCA before rising fully to VCCB. The B-side pull-up resistor sizing must also make sure that the rise time is greater than 20ns. Shorter rise times increase the pedestal overshoot shown.

Figure 8-3:

  • Point 1: A target or controller device drives low past a VILA on A-side causing the B-side re-drivers to drive to 0V.
  • Point 2: After the re-drivers reach 0V, the voltage output on B-side settles at a static voltage offset or buffered offset voltage of VOLB.

The combination of driving to 0V and releasing to a static voltage offset (VOLB) creates the inverted pedestal shown at points 1 and 2.