SCPS274B June   2021  – March 2023 TCA39306

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Switching Characteristics
    7. 6.7 Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
      1. 8.1.1 Definition of threshold voltage
      2. 8.1.2 Correct Device Set Up
      3. 8.1.3 Disconnecting a Responder from the Main Bus Using the EN Pin
      4. 8.1.4 Supporting Remote Board Insertion to Backplane with TCA39306
      5. 8.1.5 Switch Configuration
      6. 8.1.6 Controller on Side 1 or Side 2 of Device
      7. 8.1.7 LDO and TCA39306 Concerns
      8. 8.1.8 Current Limiting Resistance on VREF2
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Enable (EN) Pin
      2. 8.3.2 Voltage Translation
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 General Applications of I2C
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Bidirectional Voltage Translation
        2. 9.2.2.2 Sizing Pullup Resistors
        3. 9.2.2.3 Bandwidth
      3. 9.2.3 Application Curve
    3. 9.3 Systems Examples: I3C Usage Considerations
      1. 9.3.1 I3C Bus Switching
      2. 9.3.2 I3C Bus Voltage Translation
    4. 9.4 Power Supply Recommendations
    5. 9.5 Layout
      1. 9.5.1 Layout Guidelines
      2. 9.5.2 Layout Example
  10. 10Device and Documentation Support
    1. 10.1 Receiving Notification of Documentation Updates
    2. 10.2 Support Resources
    3. 10.3 Trademarks
    4. 10.4 Electrostatic Discharge Caution
    5. 10.5 Glossary
  11. 11Mechanical, Packaging, and Orderable Information

8.1.3 Disconnecting a Responder from the Main Bus Using the EN Pin

TCA39306 can be used as a switch to disconnect one side of the device from the main bus, whether isolating I3C and I2C devices or different speed groups. This can be advantageous in multiple situations. One instance of this situation is if there are devices on the I2C bus which only supports fast mode (400 kHz) while other devices on the bus support fast mode plus (1 MHz). An example of this is displayed in Figure 8-3.

GUID-20210519-CA0I-L4QV-4HPJ-DWQVDNJDR3CN-low.svg Figure 8-3 Example of an I2C bus with multiple supported frequencies

In this situation, if the controller is on the 1 MHz side then communicating at 1 MHz should not be attempted if TCA39306 were enabled. It needs to be disabled for the device to avoid possibly glitching state machines in devices which were designed to operate correctly at 400 kHz or slower. When the device is disabled, the controller can communicate with the 1 MHz devices without disturbing the 400 kHz bus. When the device is enabled, communication across both sides at 400 kHz is acceptable.