SCPS245D December   2012  – September 2024 TCA9517A

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 Thermal Information
    6. 5.6 Electrical Characteristics
    7. 5.7 Timing Requirements
    8. 5.8 I2C Interface 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
      1. 7.3.1 Two-Channel Bidirectional Buffer
      2. 7.3.2 Active-High Repeater-Enable Input
      3. 7.3.3 VOL B-Side Offset Voltage
      4. 7.3.4 Standard Mode and Fast Mode Support
      5. 7.3.5 Clock Stretching Support
    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 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Clock Stretching Support
        2. 8.2.2.2 VILC and Pullup Resistor Sizing
      3. 8.2.3 Application Curve
  10. 9 Power Supply Recommendations
  11. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  12. 11Device and Documentation Support
    1. 11.1 Receiving Notification of Documentation Updates
    2. 11.2 Support Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  13. 12Revision History
  14. 13Mechanical, Packaging, and Orderable Information
    1. 13.1 Tape and Reel Information
    2. 13.2 Mechanical Data

8.2.2.2 VILC and Pullup Resistor Sizing

For the TCA9517 TCA9517A to function correctly, all devices on the B-side must be able to pull the B-side below the voltage input low contention level (VILC). This means that the VOL of any device on the B-side must be below
0.4 0.45 V.

VOL of a device can be adjusted by changing the IOL through the device which is set by the pull-up resistance value. The pull-up resistance on the B-side must be carefully selected to ensure that logic levels will be transferred correctly to the A-side.

TCA9517A Typical Star Application TCA9517A Typical Star ApplicationFigure 8-2 Typical Star Application

Multiple A sides of TCA9517 TCA9517As can be connected in a star configuration, allowing all nodes to communicate with each other.

TCA9517A Typical Series Application TCA9517A Typical Series ApplicationFigure 8-3 Typical Series Application

To further extend the I2C bus for long traces/cables, multiple TCA9517 TCA9517As can be connected in series as long as the A-side is connected to the B-side. I2C bus slave devices can be connected to any of the bus segments. The number of devices that can be connected in series is limited by repeater delay/time-of-flight considerations on the maximum bus speed requirements.

TCA9517A Bus A (0.9 V to 5.5 V Bus) WaveformFigure 8-4 Bus A (0.9 V to 5.5 V Bus) Waveform
TCA9517A Bus B (2.7 V to 5.5 V Bus) Waveform TCA9517A Bus B (2.7 V to 5.5 V Bus) WaveformFigure 8-5 Bus B (2.7 V to 5.5 V Bus) Waveform