SDLS975A April   2024  – September 2025 LSF0002

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 Electrical Characteristics
    6. 5.6 Switching Characteristics (Translating Down): BN = 3.3V
    7. 5.7 Switching Characteristics (Translating Down): BN = 2.5V
    8. 5.8 Switching Characteristics (Translating Up): BN = 3.3V
    9. 5.9 Switching Characteristics (Translating Up):BN = 2.5V
  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 Auto Bidirectional Voltage Translation
      2. 7.3.2 VBIAS/ Enable
    4. 7.4 Device Functional Modes
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Open-Drain Interface (I2C, PMBus, SMBus, and GPIO)
        1. 8.2.1.1 Design Requirements
          1. 8.2.1.1.1 Enable and Disable Guidelines
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Bidirectional Translation
          2. 8.2.1.2.2 Pull-Up Resistor Sizing
        3. 8.2.1.3 Application Curve
      2. 8.2.2 Mixed-Mode Voltage Translation
      3. 8.2.3 Voltage Translation for Vref_B < Vref_A + 0.8V
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

8.2.2 Mixed-Mode Voltage Translation

The supply voltage (VEXT A,B) for each channel can be individually set with a pull-up resistor. Figure 8-3 shows an example of this mixed-mode multi-voltage translation. For additional details on multi-voltage translation, see the Multi-voltage Translation with the LSF Family video.

With VEXT,B pulled up to 5V and VEXT,A connected to 1.2V, all channels will be clamped to 1.2V at which point a pullup can be used to define the high level voltage for a given channel.

  • Push-Pull Down Translation (5V to 1.2V): Channel 2 is an example of this setup. When B2 is 5V (HIGH), A2 is clamped to 1.2V, and when B2 is 0V (LOW), A2 is driven LOW through the switch.
  • Push-Pull Up Translation (1.2V to 3.3V): Channel 1 is an example of this setup. When A1 is 1.2V, the switch is high impedance and B1 channel is pulled up to 3.3V through RB1. When A1 is LOW, B1 is driven LOW through the switch.
  • Push-Pull Down Translation (3.3V to 1.2V): Channels 1 is an example of this setup. When B1 is driven to 3.3V, A1 is clamped to 1.2V, and when B1 is LOW, A1 is driven LOW through the switch.
LSF0002 Multi-Voltage Translation Example with the LSF TranslatorsFigure 8-3 Multi-Voltage Translation Example with the LSF Translators