SCPS178C July   2007  – April 2022 PCA9306-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and Functions
  7. 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  Switching Characteristics: Translating Down, VIH = 3.3 V
    7. 7.7  Switching Characteristics: Translating Down, VIH = 2.5 V
    8. 7.8  Switching Characteristics: Translating Up, VIH = 2.3 V
    9. 7.9  Switching Characteristics: Translating Up, VIH = 1.5 V
    10. 7.10 Typical Characteristics
  8. 8 Parameter Measurement Information
  9. 9 Detailed Description
    1. 9.1 Overview
      1. 9.1.1 Definition of threshold voltage
      2. 9.1.2 Correct Device Set Up
      3. 9.1.3 Disconnecting a Target from the Main I2C Bus Using the EN Pin
      4. 9.1.4 Supporting Remote Board Insertion to Backplane with PCA9306-Q1
      5. 9.1.5 Switch Configuration
      6. 9.1.6 Controller on Side 1 or Side 2 of Device
      7. 9.1.7 LDO and PCA9306-Q1 Concerns
      8. 9.1.8 Current Limiting Resistance on VREF2
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Enable (EN) Pin
      2. 9.3.2 Voltage Translation
    4. 9.4 Device Functional Modes
  10. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 General Applications of I2C
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Bidirectional Translation
        2. 10.2.2.2 Sizing Pullup Resistor
        3. 10.2.2.3 PCA9306-Q1 Bandwidth
      3. 10.2.3 Application Curves
  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
      1. 13.1.1 Related Documentation
    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

9.1.5 Switch Configuration

PCA9306-Q1 has the capability of being used with its VREF1 voltage equal to VREF2. This essentially turns the device from a translator to a device which can be used as a switch, and in some situations this can be useful. The switch configuration is shown in Figure 9-5 and translation mode is shown in Figure 9-6.

GUID-FB26EC01-A636-46FB-9A48-24EE65128F73-low.gifFigure 9-5 Switch Configuration
GUID-3F5EE6E6-2198-4413-BF43-85C57B2FD57D-low.gifFigure 9-6 Translation Configuration

When PCA9306-Q1 is in the switch configuration (VREF1 = VREF2), the propagation delays are different compared to the translator configuration. Taking a look at the propagation delays, if the pull up resistance and capacitance on both sides of the bus are equal, then in switch mode the PCA9306-Q1 has the same propagation delay from side one to two and side two to one. The propagation delays become lower when VCC1/VCC2 is larger. For example, the propagation delay at 1.8 V is longer than at 5 V in the switching configuration. When PCA9306-Q1 is in translation mode, side one propagate lows to side two faster than side two can propagate lows to side 1. This time difference increases as the difference between VCC2 and VCC1 becomes larger.