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

9.1.8 Current Limiting Resistance on VREF2

The resistor is used to limit the current between VREF2 and VREF1 (denoted as RCC) and helps to establish the reference voltage on the enable pin. The 200k resistor can be changed to a lower value; however, the bias current proportionally increases as the resistor decreases.

Equation 5. Ibias = (VCC2 - Ven)/RCC : Ven = VREF1 + Vth

where

  • Vth is approximately 0.6V

Keep in mind RCC should not be sized low enough that ICC exceeds the absolute maximum continuous channel current specified in section 6.1 which is described in Equation 6.

Equation 6. RCC(min) ≥ (VCC2 - Ven)/0.128 : Ven = VREF1 + Vth

where

  • Vth is approximately 0.6V