SLVSHA3A March   2024  – October 2024 TPS22996H-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 Switching Characteristics
    7. 5.7 Typical DC Characteristics
    8. 5.8 Typical AC 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 ON and OFF Control
      2. 7.3.2 Input Capacitor (Optional)
      3. 7.3.3 Output Capacitor (Optional)
      4. 7.3.4 Quick Output Discharge
      5. 7.3.5 Humidity Resistance
      6. 7.3.6 Thermal Shutdown
      7. 7.3.7 Adjustable Rise Time
    4. 7.4 Device Functional Modes
  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
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
      3. 8.4.3 Power Dissipation
  10. 9 Device and Documentation Support
    1. 9.1 Receiving Notification of Documentation Updates
    2. 9.2 Support Resources
    3. 9.3 Trademarks
    4. 9.4 Electrostatic Discharge Caution
    5. 9.5 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

8.2.2 Detailed Design Procedure

The design in this example is trying to achieve 1000μs rise time for power sequencing, with both VBIAS and VIN to be 5V. From Table 7-1, the ION needs to be between 20μA and 100μA. To find the ION needed to achieve 1000μs rise time, linear interpolation can be used to estimate as below:

Equation 2. TR = (TR2 − TR1) / (ION2 − ION1) * (ION − ION1) + TR1

where:

  • TR is the desired TR, which is 1000μs
  • ION is the desired ION
  • TR1 is the first TR used for linear interpolation, which is 2350μs
  • TR2 is the second TR used for linear interpolation, which is 626μs
  • ION1 is the first ION used for linear interpolation, which is 20μA
  • ION2 is the second ION used for linear interpolation, which is 100μA

ION is calculated to be 82.6μA. To find the RT value, plug in the parameters in Equation 1.

RT = 1000 × (5V − 1.2V) / 82.6μA − 12.5kΩ = 33.5kΩ

By using the standard resistor value closest to 33.5kΩ, the typical rise time can be calculated for the actual resistor value used on board.