SLVSJ01 June   2025 TXG8122-Q1

ADVANCE INFORMATION  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions—TXG8122-Q1
  6. 5 Specifications
    1. 5.1  Absolute Maximum Ratings
    2. 5.2  ESD Ratings
    3. 5.3  Recommended Operating Conditions
    4. 5.4  Electrical Characteristics
    5. 5.5  Supply Current Characteristics
    6. 5.6  Switching Characteristics, VCCA = 3.3 ± 0.3V
    7. 5.7  Switching Characteristics, VCCA = 5 ± 0.5V
    8. 5.8  Electrical Characteristics (85°C)
    9. 5.9  Supply Current Characteristics (85°C)
    10. 5.10 Switching Characteristics, VCCA = 3.3 ± 0.3V (85°C)
    11. 5.11 Switching Characteristics, VCCA = 5 ± 0.5V (85°C)
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Bidirectional Level Translation
    4. 6.4 Device Functional Modes
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Regulatory Requirements
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Support Resources
    5. 8.5 Trademarks
    6. 8.6 Electrostatic Discharge Caution
    7. 8.7 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

6.1 Overview

The TXG8122-Q1 is a dual bidirectional translator intended for I2C or SMBus systems. This translator is able to support logic-level shifting and ground-level shifting up to ±80V. As with standard I2C systems, SDA and SCL I/O lines are open-drain and require external pull-up resistors to the systems's supply rail.

  • Idle state: When no device drives the bus, the pull-up resistors force SDA and SCL high, representing a logic '1'
  • Active low: Any device can assert a logic '0' by pulling the respective line to ground.

Select the pull-up resistor value so the I2C rise-time specification is met for the measured bus capacitance and supply voltage. For more information, see I2C Bus Pullup Resistor Calculation. TXG8122-Q1 can support Standard-mode (≤100kHz), Fast-mode (≤400kHz), and Fast-mode Plus (≤1MHz).

The Side 1 of this device works from 3V to 5.5V and Side 2 works from 2.25V to 5.5V. For best signal integrity, connect Side 1 (SDA1, SCL1) to the host controller – the MCU, SoC, or any single-master node. Connect Side (SDA2, SCL2) to the shared I2C bus that links multiple peripherals. The maximum load on Side 1 is ≤80pF and maximum load on Side 2 is ≤550pF.