JAJSCO4D November   2016  – December 2023 TPS22976

PRODUCTION DATA  

  1.   1
  2. 1 特長
  3. 2 アプリケーション
  4. 3 概要
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
    1.     Pin Functions
  7. 6 Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  ESD Ratings
    3. 6.3  Recommended Operating Conditions
    4. 6.4  Thermal Information
    5. 6.5  Electrical Characteristics (VBIAS = 5V)
    6. 6.6  Electrical Characteristics (VBIAS = 2.5V)
    7. 6.7  Switching Characteristics (TPS22976)
    8. 6.8  Switching Characteristics (TPS22976A)
    9. 6.9  Switching Characteristics (TPS22976N)
    10. 6.10 Typical DC Characteristics
    11. 6.11 Typical AC Characteristics
  8. 7 Parameter Measurement Information
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 ON and OFF Control
      2. 8.3.2 Input Capacitor (Optional)
      3. 8.3.3 Output Capacitor (Optional)
      4. 8.3.4 Quick Output Discharge (QOD) (Not Present in TPS22976N)
      5. 8.3.5 Thermal Shutdown
    4. 8.4 Device Functional Modes
  10. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Parallel Configuration
      2. 9.1.2 Standby Power Reduction
      3. 9.1.3 Power Supply Sequencing without GPIO Input
      4. 9.1.4 Reverse Current Blocking
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Inrush Current
        2. 9.2.2.2 Adjustable Rise Time
      3. 9.2.3 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
      3. 9.4.3 Power Dissipation
  11. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Developmental Support
    2. 10.2 Documentation Support
      1. 10.2.1 Related Documentation
    3. 10.3 ドキュメントの更新通知を受け取る方法
    4. 10.4 サポート・リソース
    5. 10.5 Trademarks
    6. 10.6 静電気放電に関する注意事項
    7. 10.7 用語集
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

9.2.2.1 Inrush Current

When the switch is enabled, the output capacitors must be charged up from 0 V to the set value (3.3 V in this example). This charge arrives in the form of inrush current. Inrush current can be calculated using Equation 1.

Equation 1. Inrush Current = C × dV/dt

where

  • C is the output capacitance
  • dV is the output voltage
  • dt is the rise time

The TPS22976 offers adjustable rise time for VOUT. This feature allows the user to control the inrush current during turnon. The appropriate rise time can be calculated using Table 9-1 and the inrush current equation. See Equation 2 and Equation 3.

Equation 2. 400 mA = 22 μF × 3.3 V/dt
Equation 3. dt = 181.5 μs

To ensure an inrush current of less than 400 mA, choose a CT value that yields a rise time of more than 181.5 μs. See the oscilloscope captures in the Application Curves section for an example of how the CT capacitor can be used to reduce inrush current.