SCPS267B March   2017  – February 2020 TCA9803


  1. Features
  2. Applications
  3. Description
    1.     Device Images
      1.      Simplified Schematic
  4. Revision History
  5. Device Comparison Table
  6. Pin Configuration and Functions
    1.     Pin Functions
  7. Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Timing Requirements
    7. 7.7 Switching Characteristics
    8. 7.8 Typical Characteristics
  8. Parameter Measurement Information
  9. Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Integrated Current Source
      2. 9.3.2 Ultra-Low Power Consumption
      3. 9.3.3 No Static-Voltage Offset
      4. 9.3.4 Active-High Repeater Enable Input
      5. 9.3.5 Powered Off High Impedance I2C Bus Pins on A-Side
      6. 9.3.6 Powered-Off Back-Power Protection for I2C Bus Pins
      7. 9.3.7 Clock Stretching and Multiple Master Arbitration Support
    4. 9.4 Device Functional Modes
      1. 9.4.1 Device Operation Considerations
        1. B-Side Input Low (VIL/IILC/RILC)
          1. VILC & IILC
          2. RILC
        2. Input and Output Leakage Current (IEXT-I/IEXT-O)
          1. IEXT-I
          2. IEXT-O
  10. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 Device Selection Guide
      2. 10.1.2 Special Considerations for the B-side
        1. FET or Pass-Gate Translators
        2. Buffered Translators/Level-shifters
    2. 10.2 Typical Application
      1. 10.2.1 Single Device
        1. Design Requirements
        2. Detailed Design Procedure
        3. Application Curves
      2. 10.2.2 Buffering Without Level-Shifting
        1. Design Requirements
        2. Detailed Design Procedure
        3. Application Curve
      3. 10.2.3 Parallel Device Use Case
        1. Design Requirements
        2. Detailed Design Procedure
        3. Application Curves
      4. 10.2.4 Series Device Use Case
        1. Design Requirements
        2. Detailed Design Procedure
        3. Application Curve
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Documentation Support
    2. 13.2 Receiving Notification of Documentation Updates
    3. 13.3 Support Resources
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information


The IILC parameter is the minimum amount of current that the external device must sink from the TCA980x in order for the TCA980x to accept the low on the B-side.

In order for the TCA980x to accept a low on the B-side, both VIL and IILC parameters must be satisfied. In an idle bus condition (both A and B sides are high), meeting the VIL threshold with an external device pull-down meets the IILC requirement, since the pull-down has to sink the entire ICS (current source value) current before the voltage on the pin falls.

In a contention situation (the A-side is being driven low externally, and the B-side is driven low by the TCA980x), the VIL requirement is already satisfied by the TCA980x alone (Since the output low voltage is less than the VIL threshold). In order for a device on the B-side to over-drive the A-side, it must sink the IILC value for the TCA980x to accept that the low is now being driven by the B-side. This helps reduce or eliminate overshoot during the hand off between a slave an master during a clock-stretching event, or an acknowledge.

External pull-up resistors on the B-side are not allowed for this reason. As the additional current provided by them may hinder an external device from being able to satisfy the TCA980x's IILC requirement. For more information on this and allowed external current into the device, see the Input and Output Leakage Current (IEXT-I/IEXT-O) section.