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

9.1 Overview

The PCA9306-Q1 is a dual bidirectional I2C and SMBus voltage-level translator with an enable (EN) input that operates without the use of a direction pin. The voltage supply range for VREF1 is 1.2 V to 3.3 V and the supply range for VREF2 is 1.8 V to 5.5 V.

The PCA9306-Q1 can also be used to run two buses, one at a 400-kHz operating frequency and the other at a
100-kHz operating frequency. If the two buses are operating at different frequencies, the 100-kHz bus must be isolated by using the EN pin when the 400-kHz operation of the main bus is required. If the controller is running at 400 kHz, the maximum system operating frequency may be less than 400 kHz because of the delays added by the repeater.

In I2C applications, the bus capacitance limit of 400 pF restricts the number of devices and bus length. The capacitive load on both sides of the PCA9306-Q1 must be considered when approximating the total load of the system, ensuring the sum of both sides is under 400 pF.

Both the SDA and SCL channels of the PCA9306-Q1 have the same electrical characteristics and there is minimal deviation from one output to another in voltage or propagation delay. This characteristic is a benefit over discrete transistor voltage translation solutions, because the fabrication of the switch is symmetrical. The translator provides excellent ESD protection to lower-voltage devices and at the same time protects less ESD-resistant devices.