SCPS292 July   2025 TCA9539A-Q1

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 I2C Interface Timing Requirements
    7. 5.7 RESET Timing Requirements
    8. 5.8 Switching Characteristics
    9. 5.9 Typical Characteristics
  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 I/O Port
      2. 7.3.2 RESET Input
      3. 7.3.3 Interrupt ( INT) Output
    4. 7.4 Device Functional Modes
      1. 7.4.1 Power-On Reset
    5. 7.5 Programming
      1. 7.5.1 I2C Interface
    6. 7.6 Register Map
      1. 7.6.1 Device Address
      2. 7.6.2 Control Register And Command Byte
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Calculating Junction Temperature and Power Dissipation
        2. 8.2.2.2 Minimizing ICC When I/Os Control LEDs
      3. 8.2.3 Application Curves
    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 Documentation Support
      1. 9.1.1 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 Detailed Design Procedure

The pull-up resistors, RP, for the SCL and SDA lines need to be selected appropriately and take into consideration the total capacitance of all targets on the I2C bus. The resistor value needed for minimum pull-up is a function of VCC, VOL,(max), and IOL as shown in Equation 1.

Equation 1. TCA9539A-Q1

The resistor value needed for maximum pull-up is a function of the maximum rise time, tr (300ns for fast-mode operation,
fSCL = 400kHz) and bus capacitance, Cb as shown in Equation 2.

Equation 2. TCA9539A-Q1

The maximum bus capacitance for an I2C bus must not exceed 400pF for standard-mode or fast-mode operation. The bus capacitance can be approximated by adding the capacitance of the TCA9539A-Q1, Ci for SCL or Cio for SDA, the capacitance of wires, connections, traces, and the capacitance of additional targets on the bus.

Table 8-1 Design Parameters
PARAMETERVALUE
VCC5.5V
VOL(max)0.4V
IOL3.0mA
Rp(min)1.7kΩ
fSCL400kHz
Cb200pF
tr150ns
Rp(max)885Ω
Pull-up R (between Rp(max) and Rp(min))1.2 ± 10%kΩ