JAJSOG4C July   2007  – April 2022 PCA9306-Q1

PRODUCTION DATA  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
  4. 4 Revision History
  5. 5 概要 (続き)
  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 サポート・リソース
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

10.2.2.2 Sizing Pullup Resistor

The pullup resistor value must limit the current through the pass transistor, when it is in the ON state, to about 15 mA. This ensures a pass voltage of 260 mV to 350 mV. If the current through the pass transistor is higher than 15 mA, the pass voltage also is higher in the ON state. To set the current through each pass transistor at 15 mA, the pullup resistor value is calculated as:

Equation 7. GUID-48C1B884-9CF7-475B-A7D9-7E900C9FB0A5-low.gif

Table 10-2 summarizes resistor values, reference voltages, and currents at 15 mA, 10 mA, and 3 mA. The resistor value shown in the +10% column (or a larger value) must be used to ensure that the pass voltage of the transistor is 350 mV or less. The external driver must be able to sink the total current from the resistors on both sides of the PCA9306-Q1 device at 0.175 V, although the 15 mA applies only to current flowing through the PCA9306-Q1 device.

Table 10-2 Pullup Resistor Values
PULLUP RESISTOR VALUE (Ω)(1)(2)
VDPU15 mA10 mA3 mA
NOMINAL+10%(3)NOMINAL+10%(3)NOMINAL+10%(3)
5 V31034146551215501705
3.3 V1972172953259831082
2.5 V143158215237717788
1.8 V97106145160483532
1.5 V7785115127383422
1.2 V57638594283312
(1) Calculated for VOL = 0.35 V
(2) Assumes output driver VOL = 0.175 V at stated current
(3) +10% to compensate for VDD range and resistor tolerance