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 Overview

The TCA39306 is a dual bidirectional voltage-level translator compatible with I2C, SMBus, and I3C with an enable (EN) input, and is operational from 0.9-V to 3.3-V VREF1 and 1.8-V to 5.5-V VREF2.

The device allows bidirectional voltage translations between 0.85 V and 5 V, without the use of a direction pin. The low ON-state resistance (RON) of the switch allows connections to be made with minimal propagation delay. When EN is high, the translator switch is ON, and the SCL1 and SDA1 I/O are connected to the SCL2 and SDA2 I/O, respectively, allowing bidirectional data flow between ports. When EN is low, the translator switch is off, and a high-impedance state exists between ports.

In addition to voltage translation, the TCA39306 can be used to isolate a higher speed bus from a lower speed bus by controlling the EN pin to disconnect the slower bus during fast-mode communication.

In I2C applications, the bus capacitance limit of 400 pF for Standard and Fast Modes, 550 pF for Fast Mode Plus restricts the number of devices and bus length. The capacitive load on both sides of the device must be taken into account when approximating the total load of the system, specifying the sum of both sides is under 400/550 pF.

Both the SDA and SCL channels of the device have the same electrical characteristics, and there is minimal deviation from one output to another in voltage or propagation delay. This is a benefit over discrete-transistor voltage-translation solutions, because the fabrication of the switch is symmetrical.